Pit-1 expression in human ductal invasive carcinomas of the breast positively correlates with MMP-1 and MMP-13 expression. (A) Representative set of negative and positive (1+, 2+, and 3+) Pit-1, MMP-1, and MMP-13 immunodetection in human breast invasive ductal carcinomas. Scale bar: 100 μm. (B) Representative figures of positive Pit-1, MMP-1, and MMP-13 expression in tumor cells (1), fibroblasts (2), and mononuclear inflammatory cells (MIC, 3). (C) Plots of median score values of MMP-1 and MMP-13 as a function of Pit-1 score groups, and table with the values of Spearman correlation test. n = 110 human breast tumors. MMP-1, matrix metalloproteinase-1; MMP-13, matrix metalloproteinase-13; Pit-1, POU class 1 homeobox 1.