ERBB4-positive PDT phenocopies the tumor of origin. (A) Hematoxylin and eosin (H&E) and TNFRSF8 stainings of primary tumor and PDT, passage 8. (B) Expression of TNFRSF8, I20ΔERBB4, COL29A1, and MMP9 transcripts as assessed by qRT-PCR in primary tumors (Pat) and PDTs. PDTs have the same number of patient-of-origin numbers after underscores, indicating the in vivo passages. (C) Western blot analysis of PDT lysates confirmed the expression of TNFRSF8, MMP9, and ERBB4. NS*, nonspecific band.