Life and health

CYP1A2

CYP1A2 (cytochrome P450 1A2), liver enzyme metabolizing caffeine, clozapine, theophylline, tizanidine; AhR-regulated, smoking-induced; phenotyped by paraxanthine/caffeine ratio; fluvoxamine is its strong index inhibitor.

CYP1B1

CYP1B1 (GLC3A, CYPIB1) is a human cytochrome P450 gene on chromosome 2p22.2 encoding an ER monooxygenase that hydroxylates estradiol and activates procarcinogens; mutations cause primary congenital glaucoma and Peters anomaly.

CYP21A2

CYP21A2 (CYP21B, P450c21B) is the human gene for steroid 21-hydroxylase on chromosome 6p21.3 in the RCCX module; mutations cause 21-hydroxylase deficiency, the most common form of congenital adrenal hyperplasia.

CYP24A1

CYP24A1 (24-hydroxylase) is a mitochondrial cytochrome P450 gene on chromosome 20 that catabolizes calcitriol and calcidiol via C24/C23 hydroxylation to calcitroic acid; inactivating mutations cause idiopathic infantile hypercalcemia.

CYP27A1

CYP27A1 (cytochrome P450 family 27 subfamily A member 1, formerly CYP27) is a human gene at 2q35 encoding mitochondrial sterol 27-hydroxylase, EC 1.14.15.15; biallelic variants cause cerebrotendinous xanthomatosis, treated with chenodeoxycholic acid.

CYP27B1

CYP27B1, also called 1-alpha hydroxylase or P450c1, is the human gene encoding the mitochondrial cytochrome P450 enzyme that converts 25-hydroxyvitamin D to active calcitriol; biallelic mutations cause vitamin D-dependent rickets type 1A.

CYP2A6

CYP2A6 is a human gene and liver enzyme, a cytochrome P450 that is the primary enzyme inactivating nicotine and that metabolizes coumarin and several drugs.

CYP2C19

CYP2C19 (cytochrome P450 2C19) is a liver enzyme gene metabolizing at least 10% of common drugs, including clopidogrel, PPIs, and antidepressants. Star alleles 2, 3 (no function) and 17 (increased) define metabolizer phenotypes guiding CPIC dosing guidelines.

CYP2C8

CYP2C8, cytochrome P450 2C8, a human liver drug-metabolizing enzyme on chromosome 10q24 handling about 5% of prescribed drugs including paclitaxel, amodiaquine, and repaglinide; strongly inhibited by gemfibrozil glucuronide and variable across populations.

CYP2C9

CYP2C9 (cytochrome P450 family 2 subfamily C member 9) is a liver endoplasmic-reticulum enzyme metabolizing S-warfarin, phenytoin, tolbutamide, and ibuprofen; 2 and 3 alleles reduce warfarin metabolism 30-40% and 80-90%.

CYP2D6

CYP2D6 (cytochrome P450 2D6) is a highly polymorphic liver enzyme and gene on 22q13.2 metabolizing about 25% of common drugs; star alleles yield poor, intermediate, normal, or ultrarapid metabolizer phenotypes guiding pharmacogenetic prescribing.

CYP2E1

CYP2E1 (cytochrome P450 family 2 subfamily E member 1, P450-J) is a human gene on 10q26.3 encoding an ethanol-inducible cytochrome P450 monooxygenase that oxidizes ethanol, acetone, and acetaminophen and bioactivates over 85 procarcinogens, generating reactive oxygen species linked to alcoholic liver disease.

CYP2J2

CYP2J2 (cytochrome P450 2J2, CPJ2) is a human extrahepatic cytochrome P450 epoxygenase, predominant in heart, converting arachidonic acid to EETs and metabolizing drugs such as terfenadine and ebastine.

CYP3A4

CYP3A4 (cytochrome P450 3A4) is the most abundant drug-metabolizing cytochrome P450 in human liver and intestine, handling about half of today's drugs; inhibited by grapefruit juice and clarithromycin, induced by rifampicin.

CYP3A5

CYP3A5 is a human cytochrome P450 enzyme of the CYP3A subfamily that metabolizes many drugs and steroid hormones, with activity in most adults determined by inherited genotype.

CYP4F2

CYP4F2 (cytochrome P450 family 4 subfamily F member 2, gene ID 8529) is a human liver ER ω-hydroxylase of vitamin K, vitamin E, arachidonic acid, and leukotriene B4; its V433M variant (rs2108622, CYP4F2*3) raises warfarin dose requirements.

Cyperaceae

Cyperaceae (莎草科), the sedge family of Poales: grass-like monocots with three-sided solid culms, 3-ranked leaves, and nutlets; about 5,687 species in 95 genera, sister to Juncaceae, dominant in wetlands, including papyrus.

Cyperaceae systematics and evolution

Cyperaceae systematics and evolution covers how the sedge family, about 5,687 species in 95 genera, is classified and how it evolved from a South American origin.

Cypermethrin

Cypermethrin (CAS 52315-07-8) is a type II pyrethroid insecticide with 8 isomers, acting on voltage-gated sodium channels; used in agriculture and wood preservation, with EU biocidal PT8 approval not renewed in 2026.

Cyperus

Cyperus spp., a genus of about 960 sedge species (Cyperaceae) including purple nutsedge, yellow nutsedge or tiger nut, and papyrus; cosmopolitan weeds, foods, and medicinal plants.

Cyperus esculentus

Cyperus esculentus, yellow nutsedge, chufa or tiger nut, is a perennial sedge (Cyperaceae) with edible gray tubers, a major invasive weed worldwide and a cultivated crop (var. sativus) used for Spanish horchata de chufa.

Cyperus rotundus

Cyperus rotundus, purple nutsedge or nutgrass, is a perennial C4 sedge spreading by tuber chains, one of the world's worst weeds, causing 20-90% crop losses yet used in traditional medicine.

Cypress canker

Cypress canker, or Seiridium canker, is a fungal disease of Cupressaceae caused mainly by Seiridium cardinale, first described in California in 1928 and now pandemic, especially severe on Italian cypress in the Mediterranean.

Cypress wood and its uses

Cypress wood, from the Mediterranean cypress and related species, resists fungal decay and insects, making it prized for coffins, temples, doors, boats, and furniture since antiquity.

Cyprinidae

Cyprinidae, the carp and minnow family of order Cypriniformes, is the largest freshwater fish family with over 1,840 species; toothless jaws, pharyngeal teeth, kinethmoid; recently split into several families.

Cypriniformes

Cypriniformes: the most diverse order of freshwater fishes (carps, minnows, loaches, suckers), about 3,000-4,200 species, toothless jaws with pharyngeal teeth on the fifth ceratobranchial, a Weberian apparatus, and two suborders, Cobitoidei and Cyprinoidei.

Cyprinodontidae

Cyprinodontidae, the pupfishes, is a family of oviparous Cyprinodontiformes fishes with about 10 genera and 103 species, from the Americas, northern Africa, and the Mediterranean; famous for desert spring endemics like Cyprinodon diabolis.

Cyprinodontiformes

Cyprinodontiformes (killifishes, topminnows, livebearers; Berg, 1940) is an order of about 1,250-1,350 ray-finned fishes in Atherinomorphae, with 14 families, repeated origins of viviparity and annualism, and guppies, mollies, and mosquitofish among its members.

Cypripedioideae

Cypripedioideae, the slipper orchids, is an orchid subfamily with pouch-shaped lips and two fertile anthers, in five genera (Cypripedium, Paphiopedilum, Phragmipedium, Mexipedium, Selenipedium), about 182 species, many threatened and CITES-listed.