PRRT2 and breast carcinoma: This is consistent with previous studies showing that PKC-θ is highly expressed in estrogen receptor-negative (ER-) human breast tumors and TNBC cell lines but not ER+ breast tumors or breast cancer cell lines [53,64] and further supports our previous work showing that nPKC-θ regulates inducible EMT transcription programs in breast cancer cells [6].