Cell biology

M cell of gut

M cell of gut (microfold cell), a rare specialized intestinal epithelial cell overlying Peyer's patches that lacks normal microvilli and transcytoses luminal antigens and pathogens to immune cells, initiating mucosal immunity; also exploited by pathogens and targeted for oral vaccines.

M-07e

M-07e (MO7e, Mo7e) is a human acute megakaryoblastic leukemia cell line, DSMZ ACC 104, established in 1987 from a 6-month-old girl; it is an IL-3/GM-CSF-dependent subline of M-07 used in cytokine and BCR-ABL studies.

MA-104

MA-104 (MA104) is an African green monkey fetal kidney epithelial cell line, originally mislabeled rhesus, that is highly susceptible to simian rotavirus SA11 and serves as the standard substrate for rotavirus isolation, assay, and vaccine research.

MAC-T

MAC-T (Mammary Alveolar Cells-large T antigen, CVCL_U226) is an immortalized bovine mammary epithelial cell line from a Holstein cow, SV-40 large T-antigen transfected at McGill in 1991, used for lactation and mammary biology studies.

MACF1

MACF1 (ACF7, macrophin, trabeculin-α) is a ~600-800 kDa spectraplakin protein on chromosome 1p34.3 that crosslinks microtubules and actin, mediates Wnt signaling, and whose domain-specific variants cause LISDD brain malformation, myopathy, epilepsy, and cancer promotion.

Macroautophagy

Macroautophagy (autophagy) is the conserved lysosomal degradation pathway in which double-membrane autophagosomes, built by ATG proteins from the phagophore, sequester cytoplasm; distinct from microautophagy, chaperone-mediated autophagy, and noncanonical autophagy.

Macroglial cell

Macroglial cell (macrogliocyte, CL:0000126): a neuroglial cell of ectodermal origin, the astrocytes and oligodendrocytes of the CNS considered together, distinct from mesoderm-derived microglia; myelinating, homeostatic, regionally diverse glia.

Macrophage

Macrophage: large phagocytic immune cell, also called tissue-resident macrophages (microglia, Kupffer cells, osteoclasts), discovered by Metchnikoff in the 1880s; embryonic yolk-sac origin, self-renewing, M1/M2 polarization, central to immunity, repair, and disease.

Macrophage derived foam cell

Macrophage derived foam cell: a lipid-loaded macrophage, also called foam cell, formed by scavenger-receptor uptake of modified LDL and cholesteryl ester accumulation; hallmark of atherosclerosis, also seen in tuberculosis and other infections.

Macula densa

Macula densa: densely packed columnar epithelial cells of the distal tubule at the glomerular vascular pole, forming the juxtaglomerular apparatus; senses NaCl via NKCC2 to drive tubuloglomerular feedback and renin release.

Major intrinsic protein

Major intrinsic protein (MIP, aquaporin-0/AQP0) is the dominant water channel of eye lens fiber cells, about 40% of their membrane protein; its deficiency causes cataracts and it archetypes the aquaporin/MIP superfamily.

Sep 21, 2026

Malcolm Irving

Malcolm Irving is a biophysicist and Professor of Biophysics at King's College London, elected a Fellow of the Royal Society in 2003 for his work on muscle contraction.

MAM signalling in ageing and disease

Mitochondria-associated membranes (MAMs) are 10–30 nm contact sites between the endoplasmic reticulum and mitochondria that relay calcium, ROS, and immune signals, and change with age.

Mammosomatotroph

Mammosomatotroph: a dual-hormone anterior pituitary cell (also mammosomatotrope) secreting both growth hormone and prolactin in the same cell, PIT1/ERα lineage, rare in adults, source of mammosomatotroph PitNETs causing acromegaly with hyperprolactinemia.

Sep 21, 2026

Manuel F. Morales

Manuel Francisco Morales (1919–2009) was a Honduran-born American biophysicist who spent six decades studying how muscle converts ATP's chemical energy into mechanical force, and was elected to the National Academy of Sciences in 1975.

MAP kinase activation

MAP kinase activation: switching on of ERK1/2, p38, and JNK mitogen-activated protein kinases by dual Thr/Tyr phosphorylation in the Thr-Xaa-Tyr activation-loop motif, via the conserved MAPKKK-MAPKK-MAPK three-tiered cascade.

MAP4

MAP4 (microtubule-associated protein 4), also called XMAP230, is a ubiquitous vertebrate microtubule-binding protein that stabilizes microtubules, is released by phosphorylation, and regulates dynein and kinesin organelle transport.

MAPK/ERK pathway

The MAPK/ERK pathway, also called the Ras–Raf–MEK–ERK pathway, is a chain of protein kinases that relays signals from cell-surface receptors to DNA, controlling proliferation and differentiation.

Sep 21, 2026

Marie-France Carlier

Marie-France Carlier is a French biochemist at the CNRS who studies how actin assembly drives cell movement, showing it can be reconstituted in vitro from five purified proteins.

Mark E. von Zastrow

Mark E. von Zastrow is a professor of psychiatry and pharmacology at the University of California, San Francisco, known for establishing that GPCRs continue signaling from endosomes.

Sep 29, 2026

Mass cytometry

Mass cytometry, known commercially as CyTOF, is a single-cell technique introduced in 2009 that measures over 40 cellular parameters with heavy-metal-tagged antibodies, used mainly for immune profiling.

Mast cell

Mast cell (Mastzellen), a tissue-resident granulated immune cell named by Paul Ehrlich in 1878; stores histamine and heparin, activates via IgE receptor FcεRI, depends on stem cell factor, and drives allergy, anaphylaxis, and mastocytosis.

Maternally inherited diabetes and deafness

Maternally inherited diabetes and deafness (MIDD), also called Ballinger-Wallace syndrome, is a mitochondrial DNA disorder, usually m.3243A>G in MT-TL1, causing diabetes plus progressive hearing loss, inherited only from mothers, in about 1% of diabetes cases.

Sep 29, 2026

Matrigel invasion assay

The Matrigel invasion assay is a cell biology assay that measures the ability of cells, typically cancer cells, to penetrate a layer of Matrigel as a readout of invasive potential.

Matrix Gla protein

Matrix Gla protein, or MGP, is a vitamin K-dependent extracellular matrix protein secreted by vascular smooth muscle cells and chondrocytes that binds calcium and inhibits arterial calcification.

MCAS

MCAS (CVCL_3020) is a human ovarian mucinous cystadenocarcinoma cancer cell line established in 1985 from a 60-year-old Japanese woman, carrying KRAS G12D, CDKN2A, PIK3CA, SMAD4, and TP53 mutations and used as a mucinous ovarian carcinoma model.

MCF-10A

MCF-10A (Michigan Cancer Foundation-10A) is a non-tumorigenic, spontaneously immortalized human breast epithelial cell line isolated in 1984 from fibrocystic breast tissue, ATCC CRL-10317, used as a normal-like breast model and 3D acini culture system.

MCF-7

MCF-7 (Michigan Cancer Foundation-7, CVCL_0031, ATCC HTB-22) is the first hormone-responsive human breast adenocarcinoma cell line, established 1973 from a pleural effusion; ER-positive, luminal A, the most published breast cancer cell line, with documented inter-laboratory heterogeneity.

MDA-MB-231

MDA-MB-231 (MD Anderson-Metastatic Breast-231, RRID:CVCL_0062) is a triple-negative human breast adenocarcinoma cell line established in 1973 from a pleural effusion, widely used in metastatic breast cancer and drug screening research.