ESR1 and cancer: Our protein panel comprises targets having accepted utility in cancer subtype classification (ER, HER2 and epidermal growth factor receptor (EGFR) oncoproteins), cancer cell identification (epithelial cell adhesion molecule (EpCAM), panCK and CK8 expression), known expression in mammalian cells (glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and β-tubulin) and indicative of white blood cells (WBCs; for example, high CD45, negative for EpCAM, panCK and CK8).