PTPRC and acute lymphoblastic leukemia: To further confirm CML specificity of PB CD26+ LSCs flow cytometry assessment, we tested for the presence of CD45+/CD34+/CD38−/CD26+ cells a consistent number of PB samples from patients affected by other blood disorders, such as idiopathic myelofibrosis (IMF) (12 samples) Ph+ acute lymphoblastic leukemia (Ph+ ALL, 5 samples) AML (10 samples).