BRAF and plasma cell myeloma: Although exposing BRAF-mutated myeloma cell lines to BRAF inhibition in vitro causes a reduction in RAS-pathway activity, the opposite effect is seen in BRAF wt cells, especially when a RAS mutation is also present.11 This paradoxical effect indicates that BRAF inhibitor treatment may be harmful in patients with small BRAF V600E-mutated subclones, underlining the need of accurate characterization of candidates for BRAF inhibitor treatment.