MUC1 over-expression is associated with tumor progression and poor prognosis [22] and is reported to diminish apoptosis signalled through the intrinsic pathway [13]–[15], [18]–[20] and enhance VEGF expression in some cancer cells in vitro[17], [42], [43] – cellular activities that we have linked to differences in intrinsic Δψm of subcloned mammary and colonic carcinoma cell lines [1], [2], [41]. The gene discussed is MUC1; the disease is cancer.