To our surprise, PIM1 inhibition with AZD‐1208 led to enhanced NF‐κB activation, as estimated by phosphorylation of p65 (RELA), and potentiated BCR activation, as estimated by downstream kinases (pSYKTyr525/526 and pBTKTyr223), in three ABC‐DLBCL cell lines with PIM1 mutation. Here, RELA is linked to aneurysmal bone cyst.