ERBB2 and cancer: Of note, PE/CA-PJ49 CtxR cells were also resistant to the EGFR-targeted tyrosine kinase inhibitor (TKI) erlotinib and the dual EGFR/HER2-targeted TKIs afatinib and lapatinib (S2 Fig), but remained sensitive to cisplatin and CBL0137, a novel anti-cancer agent targeting the facilitates chromatin transcription (FACT) complex [31,32] (S3 Fig), suggesting cross-resistance to EGFR targeting but not general treatment resistance.