IL6 and Alzheimer disease: [6], [7] Recently, five previous studies were also frequently performed on the effect of IL-6-572 C/G polymorphism on AD, but the results were conflicting.[8]–[12] Two previous meta-analyses [13], [14] regarding IL-6-174 G/C polymorphisms and AD have summarized the findings from certain studies, but a number of important studies were missed.