CYP27B1 and leprosy: The fact that the robust expression of type I IFN and downstream genes along with low CYP27B1 expression is characteristic of L-lep lesions and vice versa in T-lep lesions [17], suggests that the ability of type I IFN to inhibit CYP27B1 contributes to the outcome of the host response against mycobacteria in leprosy.