TERT and cancer: Mutation of the TERT promoter, one of the mostly commonly found non-coding mutations in cancer (Mularoni et al., 2016; ICGC/TCGA Pan-Cancer Analysis of Whole Genomes Consortium, 2020), leads to telomerase upregulation via allele-specific epigenetic alterations involving PRC2 and DNA methylation (Leão et al., 2019; Lee et al., 2019; Stern et al., 2017).