POU5F1 and neoplasm: The tumor-restricted TcGT most frequently detected in our cohort initiated within a primate-specific LTR66 endogenous retroviral promoter on chromosome 8q24, spliced into several other TE inserts (AluSx1, LTR33, L2b, and MLT1F1) and ended in POU5F1B, a paralog of the POU5F1/OCT4 pluripotency gene.