CCR9 and melanoma: As expected, stable CCR9 knockdown tumor cell variants were more susceptible to immune lysis by melanoma patient-derived tumor-infiltrating lymphocytes (TIL 209) than their counterparts in the chromium-release cytotoxicity assay (Fig7A), with no significant difference noted on the surface HLA-A2 expression upon CCR9 knockdown (Supplementary Fig S7B).