Reverse Transcription quantitative Polymerase Chain Reaction (RT-qPCR) is a method of choice for quantifying micro RNAs (miRNAs). Typically, RT-qPCR data are normalized to reference genes. While miRNAs are used for diagnosing and subtyping breast cancer, various studies show their deregulation in this condition, thus, undermining miRNAs' utility as a reference. This review examines the expression pattern of miR-16 and suggests normalization approaches for breast cancer. We analyzed the data from selected peer-reviewed studies to calculate the standardized mean difference (SMD) with subsequent Chi-square testing and identified the difference in miR-16 expression between breast cancer patients and healthy controls. With a negative SMD value of-0.56 and Chi-square of 62.62 (p-value = 0.05), the deregulation of miR-16 in breast cancer was confirmed. High variance in the stability value (SV) of miR-16 expression levels confirmed its inappropriateness as a control gene in breast cancer. The combination of miR-16 and miR-425 was confirmed as an accurate endogenous control.

To clarify the association between microsomal epoxide hydrolase gene (EPHX1) Tyr113His polymorphism and hepatocellular carcinoma (HCC) risk, a meta-analysis was performed. Overall, EPHX1 Tyr113His polymorphism was associated with increased risk of HCC. Subgroup analyses by status of Hardy-Weinberg equilibrium (HWE) in controls further confirmed this association. Through a literature search, 119 relevant records were identified, and 17 individual case-control studies from 13 publications were finally included, involving a total of 1,480 HCC cases and 2,564 controls. In subgroup analyses, increased associations were found in Asians, Caucasians, hepatitis B virus (HBV)- dominant areas, hepatitis C virus (HCV)-dominant areas, high-rate areas of HCC, and medium-rate areas of HCC, but not in Africans and low-rate areas of HCC, respectively. This meta-analysis suggests that EPHX1 Tyr113His polymorphism contributes to HCC risk.