C-4 methylsterol oxidase activity https://github.com/geneontology/go-ontology/issues/23278 https://github.com/geneontology/go-ontology/issues/25815 https://github.com/geneontology/go-ontology/issues/30193 4-methylsterol oxidase activity Reactome:R-HSA-194641 methylsterol monooxygenase activity molecular_function Catalysis of the reaction: 4,4-dimethyl-5alpha-cholest-7-en-3beta-ol + 6 Fe(II)-[cytochrome b5] + 5 H+ + 3 O2 = 4alpha-carboxy-4beta-methyl-5alpha-cholest-7-ene-3beta-ol + 6 Fe(III)-[cytochrome b5] + 4 H2O. Reactome:R-HSA-9947203 methylsterol hydroxylase activity MetaCyc:RXN-13188 Reactome:R-HSA-194669 Reactome:R-HSA-9947207 RHEA:55220 EC:1.14.18.9 GO:0000254 oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, another compound as one donor, and incorporation of one atom of oxygen