CYP27B1 encodes the human gene, Cytochrome P450 family 27 subfamily B member 1. It may also be known as: 25-hydroxyvitamin D-1 alpha hydroxylase, mitochondrial; 25-OHD-1 alpha-hydroxylase; 25-hydroxyvitamin D(3) 1-alpha-hydroxylase; VD3 1A hydroxylase; Calcidiol 1-monooxygenase; Cytochrome P450 subfamily XXVIIB polypeptide 1; Cytochrome P450C1 alpha; Cytochrome P450VD1-alpha; Cytochrome p450 27B1; 25-hydroxyvitamin D-1 alpha hydroxylase, mitochondrial ; VDDR I; 1alpha(OH)ase; 25-Hydroxyvitamin D3 1alpha-hydroxylase; CP2B; CYP1alpha; CYP27B; P450c1; PDDR; VDD1; VDDR; VDDRI; cytochrome P450, family 27, subfamily B, polypeptide 1. The encoded protein is an enzyme with an amino acid length of 508 and a mass of 56.5 kDa. Other isoforms may exist. Homologs of this gene exist in other organisms, including: Mouse, Rat, Frog.