CD44 and neoplasm: Regarding phenotype separation techniques, it is accepted that the immunomagnetic separation of tumour cells using the CD44 marker, which is a marker for many types of cancer stem cells, including breast CSCs, allows lineages with greater tumourigenicity and metastatic potential to be obtained from breast tumours [12], as well as colorectal [16], pancreatic [15], and prostate tumours [18].