FOXO1 and mantle cell lymphoma: The sgRNA/cDNA rescue assays showed that ectopic expression of the FOXO3-1 variant containing the FLAG-tagged FOXO3 N-terminus (1–296 aa) and the FOXO1 C-terminus (299–655 aa) retained full functionality and could compensate for endogenous FOXO1 depletion in sgFOXO1-transduced CCMCL1 and UPN1 MCL cells (Figure 5E and Supplemental Figure 6, C–E).