Therefore, we first determined levels of TERT mRNA and/or telomerase activity in 6 MCC cell lines and 43 tumors [33 formalin-fixed, paraffin-embedded (FFPE) and 15 frozen samples; both FFPE and frozen tumor samples were available from 5 patients] obtained from 35 patients with MCC (Table 1 and Supplementary Table S1). This evidence concerns the gene TERT and Merkel cell skin cancer.