SLC6A13 and Pseudofolliculitis barbae: Likewise, the following marker genes were selected for analysis in PF tumours: LAMA2, ALDH1L1, SLC6A13, IGSF1, and CXorf67 for PFA; and NELL2, DNAH1, CEP83, C9orf72, and NXNL2 for PFB tumours.