A large-scale plasma proteome analysis screened leukemia inhibitory factor (LIF) as a new peripheral blood protein marker for predicting ICI efficacy in multiple cancers.[20] Using the Olink Immuno-Oncology panel (92 proteins) with proximity extension assays (PEA), Gao demonstrated the associations between IL-8, TIE2 and HGF and prognosis among patients with esophageal cancer [19]. Here, CXCL8 is linked to esophageal cancer.