SYP and adenocarcinoma: Histologically, NEPC tumors were composed of sheets and nests of medium-sized to large cells with high nuclear to cytoplasmic ratio and/or anaplastic morphology (Figure 6B), expressing the NEPC marker synaptophysin (SYP) and either negative (in case of “pure” NEPC, as shown in Figure 6C) or positive for CK8 [in case of NEPC tumors with mixed adenocarcinoma and NE features, ref. (5), as shown in Supplementary Figure 1A].