After 24, 48, or 72 h of treatment, JuB (40, 80, or 120 μM) inhibited the growth of human histiocytic lymphoma U937 cells and exerted antileukemic effects by dose-dependently activating the receptor-interacting protein kinase 1 (RIPK1)/RIPK3/mixed lineage kinase domain-like pseudokinase (MLKL) pathway, inducing necroptosis. Here, RIPK1 is linked to reticulum cell sarcoma.