It is usually assumed that approximately the 85–90% of the tumors utilize telomerase, while the other 10–15% of tumors utilize ALT for telomere maintenance [15]; but a very recent study, performed on 18,430 samples across 31 cancer types, demonstrated that the 73% of the analyzed samples expressed TERT, the 5% was associated with ALT, while the remaining 22% of tumors neither expressed TERT nor harbored ALT-associated alterations [25]. This evidence concerns the gene TERT and cancer.