Tacalcitol is a synthetic analogue of 1,25 dihydroxyvitamin D3, available as ointment (4 μg/g); it is used for the treatment of psoriasis, and in combination with NB-UVB phototherapy, applied twice a week, it shows synergism in the treatment of generalized vitiligo by increasing c-Kit mRNA (receptor tyrosine kinase protein in humans encoded by the KIT gene) expression in irradiated melanocytes [86]. Here, KIT is linked to psoriasis.