MCC and Merkel cell skin cancer: Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) analysis using isoform-specific primers (Fig. 2B), as expected, showed that HFFs and variant MCC cells expressed mostly isoform 1 mRNA (Fig. 2C, top) while HFK and classical VP-MCC cells predominantly expressed isoform 3 mRNA (Fig. 2C, bottom).