Trop2 is expressed in normal human tissues, including breast, cervix, kidney, lung and pancreas, and is upregulated in all cancers, regardless of baseline Trop2 expression. It’s a 35-kDa transmembrane glycoprotein and calcium signal transducer encoded by the TACSTD2 gene, and is structurally related to epithelial cell adhesion molecule (EpCAM). It participates in embryonic development and is implicated in several oncogenetic signaling pathways that lead to proliferation, including the MAPK–ERK1–ERK2 pathway, nuclear factor (NF)-κB and RAF.