LIF and neoplasm: In two independent prospective tumor cohorts treated with ICIs (discovery cohort, n = 95; validation cohort, n = 292), it was found through the Olink® plasma proteome that the level of leukemia inhibitory factor (LIF) in baseline blood had a good predictive value for therapeutic benefit (training set, AUC = 0.735; validation set, AUC = 0.622) (172).