CXCL8 and breast cancer: The results showed that cytokines secretion was reduced on KTN1 knockdown, including CXCL8 protein, which was previously shown to be essential for breast cancer growth previously.21 Then, we verified that knockdown of KTN1 reduced the secretions of CXCL8 in the supernatant of MDA-MB-231 and BT549 cell lines using enzyme-linked immune-sorbent assay (ELISA) (Fig. 3g).