MYC or IRF4 overexpression fails to rescue for loss of Ikaros. (A) Western blot of OPM2 IKZF1 gRNA clones IK20-1 and IK20-2 or EV cells transduced with either MYC MSCV-IRES-GFP (MYC-MIG) or EV-MIG control 4 days postdox treatment. Membranes were probed for Ikaros, MYC, and GAPDH. (B) CTG cell viability time course of samples described in (A) at the indicated days after treatment with dox. Data are the mean ± SD from 3 experiments. (C) Western blot of MM1S IKZF1 gRNA clone IK20-1 or EV cells transduced with either MYC MSCV-IRES-GFP (MYC-MIG) or EV-MIG control 4 days postdox. Membranes were probed for Ikaros, MYC, and GAPDH. (D) Cell viability time course of samples described in (C) after treatment with dox. Data are the mean ± SD from 3 experiments. (E) Western blot of OPM2 IKZF1 gRNA clone IK20-1 transduced with either HA-tagged full-length IRF4 MIG (IRF4-3xHA), an EV-MIG negative control, or a CRISPR-resistant IKZF1 construct (IKZF1s-3xHA). Membranes were probed with anti-HA and GAPDH 3 days postdox treatment. (A,C,E) MW are indicated to the right of the plots, GAPDH is a loading control. (F) CTG viability assay of samples described in panel E, 10 days after dox treatment. Relative cell viability vs non-dox-treated control normalized to IKZF1s-3xHA (set to 100%) is shown. Data are the mean ± SD from 3 experiments.