Anti-42A antibodies are used in antigen-specific immunodetection in biological samples. The target 42A is a known alias name of the protein S100 calcium binding protein A4, encoded by the S100A4 gene in humans. This 101-amino acid residue protein is reported to be a calcium-binding protein that plays a role in various cellular processes including motility, angiogenesis, cell differentiation, apoptosis, and autophagy. It is localized to the nucleus, cytoplasm, and is secreted of the cell. In terms of tissue expression, it is ubiquitously expressed across many tissue types. The term 18A2 is another synonym for 42A.