PIM1 and neuroblastoma: In order to determine whether inhibition of PIM1 may enhance the efficacy of ALK inhibitors in ALK-positive NB, CHLA-20 (MYCN-WT) and KELLY (MYCN-amplified) cells were transduced with a PIM1-targeting shRNA, achieving an approximate 50% reduction in PIM1 expression as confirmed by RT-qPCR (Fig. 3d, e).