CXCR1 and breast carcinoma: For instance, targeting Lgr5 in colorectal cancer, DLL3 in pulmonary neuroendocrine tumors (Morgensztern et al, 2019; Saunders et al, 2015), and CXCR1 in breast cancer has been reported to reduce the CSC population (Ginestier et al, 2010).