Despite the inability of MCT4 intron retention to be used alone as molecular signature to distinguish melanoma from BCC and SCC cancers (Figure 2A,B), the MCT4 transcriptional upregulation in BCC and SCC cancer versus healthy matched tissues, as indicated by the amplification profiles of 178 bp PCR fragment (Figure 2A), could be successfully exploited as a powerful BCC and SCC diagnostic marker for each disease. The gene discussed is SLC16A3; the disease is cancer.