Cadmium (Cd) is an environmental toxic heavy metal that predominantly causes renal failure. Although changes in gene expression are important factors affecting Cd toxicity, the genes that determine Cd toxicity have not been identified. In this study, we tested 36 genes that are highly expressed in the kidney for their effects on Cd toxicity. After human proximal tubular cells (HK-2 cells) were transfected with small interfering RNAs (siRNAs) targeting these genes, Cd toxicity was examined. The expression of the five genes selected from the primary screen was knocked down and the effect on Cd toxicity evaluated. The knockdown of CRYAA and DPYS significantly enhanced Cd toxicity, but not the toxicity of mercury compounds. The CRYAA protein plays a chaperone role and DPYS protein regulates nucleic acid metabolism. The regulation of CRYAA and DPYS expression may affect the Cd renal toxicity.