STRING 9.05 
CYP2R1 [ENSP00000334592]
cytochrome P450, family 2, subfamily R, polypeptide 1; Has a D-25-hydroxylase activity on both forms of vitamin D, vitamin D(2) and D(3)
CYP27B1 [ENSP00000228606]
cytochrome P450, family 27, subfamily B, polypeptide 1; Catalyzes the conversion of 25-hydroxyvitamin D3 (25(OH)D) to 1-alpha,25-dihydroxyvitamin D3 (1,25(OH)2D) plays an important role in normal bone growth, calcium metabolism, and tissue differentiation
Evidence suggesting a functional link:
Neighborhood in the Genome:  
none / insignificant.
Gene Fusions:  
none / insignificant.
Cooccurence Across Genomes:   yes (score 0.518).  
none / insignificant.
Experimental/Biochemical Data:  
none / insignificant.
Association in Curated Databases:   yes (score 0.900).  
Co-Mentioned in PubMed Abstracts:   yes (score 0.784).  
Combined Score:
Note: the two proteins have some sequence similarity (143.9 bits over 468 amino acids. click here to see the alignment).