INSM1 and neoplasm: However, in keeping with human tumor data demonstrating that PROX1 is expressed in AR activity–low or DNPC tumors that do not harbor an NEPC differentiation program, our results demonstrate that transient PROX1 overexpression in ARPC cells led to a minor increase in expression of the NEPC marker INSM1 but even less for other NEPC markers (e.g., SYP or CHGA).