FANCM and Bone marrow hypocellularity: The importance of FANCM in mammals was first suggested in 2004, when biallelic FANCM PV was identified in a FA patient.14 However, it was later found that the patient also harbored biallelic pathogenic FANCA PV.15 Due to the lack of further reports of biallelic PV in FA patients, it was not clear whether FANCM PV are causative for FA until recently when Bogliolo et al..16 and Catucci et al.17 reported that biallelic FANCM PV increased the risks of ICL sensitivity, early-onset cancers, and chemotherapy/radiotherapy-induced pancytopenia, but did not cause bone marrow failure.