FOXO family mutations occur infrequently in CLL patients, with analysis of the ICGC database (containing data from 551 CLL patients) showing that single base substitutions within FOXO family genes occurred in 4% (22/551) of CLL patients, of which 2% (11/551) occurred in FOXO1, with a functionally “high impact” missense mutation of FOXO1 encoded in just one patient (104). This evidence concerns the gene FOXO1 and B-cell chronic lymphocytic leukemia.