CD27 and chronic myelogenous leukemia, BCR-ABL1 positive: The combination of CD27 and G0M split the CML LSK fraction into four factions: G0M+CD27+ (double positive: DP), G0M−CD27+ (single positive: SP), G0M+CD27−, and G0M−CD27− (double negative: DN) (Fig. 1c).