As shown in Figure 3, the melanoma cell lines used in the study differ in their basal level of VDR expression, and the transcript is absent in SK-MEL-188b, which is not responsive to vitamin D. Theoretically, an alternative splicing of VDR pre-mRNA may results in the production of at least five alternative transcripts (Figure 6A); thus, the unique set of primers was designed in order to detect specific variants of VDR mRNA (Table S1). The gene discussed is VDR; the disease is melanoma.