LY6S and chronic myelogenous leukemia, BCR-ABL1 positive: With the rise of the cancer stem cell hypothesis some have explored Ly6a/Sca-1 expression on cells capable of initiating cancers and have found Ly6a/Sca-1 present in the cancer initiating cells including chronic myelogenous leukemia [22], mammary carcinoma [23] and osteosarcoma [24].