MUC1 and colon carcinoma: Because the cytoplasmic domain of MUC1 C-ter (MUC1-CD) has been linked to transcriptional regulation of VEGF [15]–[17] and our data show that the levels of MUC1 C-ter in the PMF – which encompasses cytoplasmic components - are related to the intrinsic Δψm (Figure 1B), we investigated the effect of siRNA induced MUC1 down regulation on steady state VEGF secretion in colonic carcinoma cells with different Δψm.