To validate the reliability of C4.4A as a tumour marker, particularly for colorectal cancer, expression of C4.4A was compared with galectin-3, EpCAM and CO-029 expression, that all three have been described to be upregulated in colorectal cancer (Sela et al, 1989; Armstrong and Eck, 2003; Nagy et al, 2003). The gene discussed is TSPAN8; the disease is neoplasm.