Estrogen pathway for mammary density
HSD3B1,
HSD17B1
(cytochrome' P450)
CYP27B1, CYP24 metabolizes enzymes in mammary cells, Vitamin D elongates breast
CYP1A1
CYP1A2
CYP17A1
CYP19A1
CYP1B1
COMT-catechol-O-methyltransferase
UGT1A1-uridine diphospho-glucuronosyltransferase -(catalyzes estrogen)
SULT1A1, SULT1E1- sulfotransferases
ESR1, ESR2-estrogen receptors alpha and beta



CYP17 and CYP1A1-1 play a role in the pathogenesis of fibroadenoma. Meaning something like cigarette smoke can have direct role on the CYP1A1 enzyme metabolism, e.g. progression of fibroadenomas. In other words, as bad as smoking is, 2nd hand smoke can further exacerbate fibroadenomas.