PRKDC and Bone marrow hypocellularity: The involvement of DNA-PKcs in replication stress response was further demonstrated by the DNA-PKcs ‘3A’ knockin mutant mice, which harbor three alanine substitutions at the mouse DNA-PKcs Thr2605 cluster (human Thr2609 cluster) and develop congenital bone marrow failure and premature lethality due to impaired proliferation and excessive DNA damage accumulation in the hematopoietic stem cells (19).