CTNND1 and breast cancer: Catenin delta 1 (CTNND1) is an intracellular signaling protein that promotes E-calmodulin-mediated inhibition of tumor invasion and metastasis.98, 99, 100 Increased cytoplasmic localization of CTNND1 was found to be highly correlated with an enhanced invasive phenotype of E-calmodulin-deficient BC.