Using actin, alpha 2, smooth muscle, aorta (ACTA2) and calponin (CNN1) as SM markers in an analysis of human PCa specimens in the Human Protein Atlas (http://www.proteinatlas.org; Uhlen et al., 2015), we found the expected large proportion of SM in the normal human prostate, and disruption of the well-organized SM layers in PCa samples, especially more advanced tumors (Fig. 1A-F; Fig. S1, S2). Here, ACTA2 is linked to posterior cortical atrophy.