MUC1 and colon carcinoma: However, we also found that siRNA-induced down-regulation of MUC1 in colonic carcinoma cells with elevated intrinsic Δψm to levels comparable to those in cells with lower Δψm does not affect the intrinsic Δψm or Δψm-linked tumor phenotypes, including the decreased sensitivity to chemoprotective NaB induced apoptosis and the increased constitutive, hypoxia-independent VEGF secretion that are characteristic of cells with elevated intrinsic Δψm [1], [2].