Inhibition of MYD88/IRAK signaling induces apoptosis of MYD88 L265P-expressing WM cells. (A) Survival assessed by annexin V/PI staining for MYD88 L265P-expressing WM cell lines. (B-D) Statistical analysis for annexin V–positive cells following treatment with (lane i) DMSO, (lane ii) an IRAK 1 and 4 kinase inhibitor, (lane iii) a control peptide, or (lane iv) peptide inhibitor of MYD88 homodimerization with results of 3 repeat experiments for (B) BCWM.1 and (C) MWCL-1 cells and (D) MYD88 L265P-genotyped primary WM patient LPL cells and MYD88 WT healthy donor B cells depicted. P value and numbers of patients are shown as labeled. DMSO, dimethyl sulfoxide.