Taken together, our analyses of LGR5 transcript and protein levels in healthy tissues and malignancies establish that: (i) LGR5 overexpression is specific to a discrete set of cancer types; (ii) there is a substantial window of LGR5 expression between CRC, HCC, some ALL cases and healthy tissue; and (iii) the use of specific and well-validated antibodies such as α-LGR5 are a valuable diagnostic tool. The gene discussed is LGR5; the disease is cancer.