PODXL and breast carcinoma: Since its first discovery as a stem cell marker in testicular cancer [50], PODXL has been detected in several solid human malignancies, including germ cell tumours [50], astrocytoma [51], haematological cancers [52,53], and numerous epithelial malignancies including cancers of the breast, kidney, colon or rectum, prostate, pancreatic ducts, urothelial bladder, ovary, lung, thyroid, oesophagus, oral squamous cells, uterus, and stomach (Table 1).