Included studies that met the criteria had their extracted data in accordance to: name of first author, year of publication, region of study, sample size, age, type of biomarkers used (CD163, CD68 or both and PD-L1), stage of cancer (TNM stage), location of tumour analysed, follow-up, cut-off values (threshold for prognostic factor and corresponding outcome based on high-risk and low-risk groups) and univariate and/or multivariate analysis outcomes to extract HR and 95% Cl for OS. The gene discussed is CD274; the disease is cancer.