LuCaP derived from CRPC-adenocarcinoma stained negative for Pax5 expression, whereas t-NEPC LuCaP PDXs (LuCaP 93, LuCaP 145.1 LuCaP 145.2, and LuCaP 173.1), expressed high Pax5 although LuCaP 173.1 showed lower expression compared to others. The gene discussed is PAX5; the disease is adenocarcinoma.