POT1 and cancer: Consistent with cancer-associated POT1 mutations causing telomere deprotection, expression of POT1 OB-fold mutations in human cells results in rapid telomere elongation, telomere fragility, and ATR activation (Ramsay et al. 2013; Shi et al. 2014; Calvete et al. 2015; Pinzaru et al. 2016).