TTP and OS stratified by RAS mutation status. TTP stratified by NRAS mutation status in (A) bortezomib-treated patients and (B) dexamethasone-treated patients. TTP stratified by KRAS mutation status in (C) bortezomib-treated patients and (D) dexamethasone-treated patients. OS stratified by NRAS mutation status in (E) bortezomib-treated patients and (F) dexamethasone-treated patients. OS stratified by KRAS mutation status in (G) bortezomib-treated patients and (H) dexamethasone-treated patients. Each panel shows Cox proportional HR estimates (plus 95% CI) and P values based on a pairwise log-rank test.