DPP4 and chronic myelogenous leukemia, BCR-ABL1 positive: Furthermore, using gene array, qPCR, and flow cytometric analyses, Hermann et al. reported that CD34+CD38−CD26+ but not CD34+CD38−CD26− LSCs obtained from chronic-phase CML patients contained BCR/ABL1 mRNA, exhibited repopulating capability in NSG mice, and were highly expressed in imatinib-nonresponder patients, suggesting that CD26 is a highly specific CML LSC biomarker and a potential therapeutic target [44,45].