RPS6KB2 and chronic myelogenous leukemia, BCR-ABL1 positive: However, to our surprise, several dipeptide species were markedly increased in CML-KLS+ cells compared with normal KLS+ cells, whether the latter cells were isolated from healthy littermate (FVB/N) mice (Fig. 1c; Supplementary Fig. 1) or from healthy C57BL/6 control mice at 8 or 24 weeks of age (Supplementary Data 1).