MUC4 and mucinous adenocarcinoma: In spite of the small number of cases reported in this study (IMPC, n = 8, IDC, n = 10, ILC, n = 20; mucinous carcinoma, n = 10), the data showed a statistically significant increase in mRNA MUC4 levels in IMPC with respect to those in mucinous carcinoma (Fig. 2f, P = 0.0164).