In order to provide evidence that calcipotriol treatment could have a clinical benefit in RDEB, we then investigated the responsiveness of 5 different RDEB keratinocyte cell lines to calcipotriol using induction of cathelicidin (henceforth referred to as hCAP18), a direct VDR-target gene, as a readout. The gene discussed is VDR; the disease is recessive dystrophic epidermolysis bullosa.