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. The gene discussed is ALDH1L1; the disease is Pseudofolliculitis barbae.