PIP and breast cancer: Immunohistochemistry may be of limited value, as often most breast-related markers can be expressed only faintly and focally by BCC, with the exceptions of mammaglobin, gross cystic disease fluid protein 15 (GCDFP-15) or α-Methylacyl-CoA racemase (AMACR; P504S)—the latter being useful when faced with apocrine BC [25].