These findings reveal the critical importance of IL-26 on EGFR-TKI resistance in TNBC, and serve as the basis for a novel therapeutic strategy in TNBC, as well as potentially other EGFR-TKI resistant cancers such as non-small cell lung cancer or colorectal cancer, with the combination of anti-IL-26 mAb and anti-EGFR agents. Here, EGFR is linked to colorectal cancer.