Further, incubation of the EpCAM+ colon carcinoma cell line DLD-1 with anti-EpCAM:CD40L showed a strong anti-CD40L fluorescence signal (Figure 2B; left panel) that was completely inhibited by pre-incubation with an epitope-competing EpCAM-blocking antibody (Figure 2B, middle panel). Here, EPCAM is linked to colon carcinoma.