To better understand the effect of VDR expression on the differential action of vitamin D3 analogs, we used three human melanoma lines, A375 and WM98 and a subline b of SKMEL-188 which lost responsiveness to vitamin D during in vitro passaging [55], and detected the VDR expression and sensitivity to selected vitamin D analogs (1,25(OH)2D3, 25(OH)D3, 21(OH)pD and calcipotriol). The gene discussed is VDR; the disease is melanoma.