ERK1/2 activation in BTK^Cys481Serexpressing MYD88-mutated cells triggers prosurvival and inflammatory cytokine release in ibrutinib-treated cells. Cytokine production relative to untreated BTK^WT or BTK^C481S expressing BCWM.1 WM (A) and TMD8 ABC DLBCL (B) cells is shown following treatment with either vehicle control (DMSO), ibrutinib, ulixertinib, or combination of ibrutinib and ulixertinib. Fold changes are indicated by the color scale, and dark red boxes indicate scales above the highest range (≥2.39).