Thus, we analysed the UPS inhibitory effects of b‐AP15 in BCR‐ABLWT (KBM5, K562, and BaF3) and BCR‐ABLT315I (KBM5‐T315I and BaF3‐T315I) CML cells. The gene discussed is PPIB; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.