The present study analyzed the gene expressions of MMP2, MMP9, CLDN5, OCLN, ZO1, AQP1 and AQP4, in the brains of forensic autopsy cases, using reverse transcription quantitative PCR (RT-qPCR), combined with immunohistochemical detections, to investigate the molecular pathology of brain edema in fatal heat stroke cases with special regard to the importance of reference gene selection. The gene discussed is AQP4; the disease is Heat Stroke.