ACP6 and hepatocellular carcinoma: The overall forest plot of SMD and SROC curves generated through pooling expression data of ACP6 in HCC and non-cancer liver samples from all included RNA-seq dataset and microarrays confirmed the significant overexpression of ACP6 in HCC tissues and the preferable discriminatory ability of ACP6 expression for HCC (SMD = 0.69, 95%CI = 0.56–0.83) (AUC = 0.71, 95%CI = 0.67–0.75) (Additional file 6).