IL10 and Familial prostate cancer: This study purported to investigate the impact of interleukin-10 (IL-10) gene 4 polymorphisms (−1082G>A, -819T>C, -592A>C and 210T>C) on peripheral blood IL-10 variation and prostate cancer (PCa) risk, with a special consideration given to various origins of between-study heterogeneity.