After generating FABP4 knockout (FABP4−/−) transgenic adenocarcinoma of the mouse prostate (TRAMP) mice, it was found that FABP4−/− TRAMP mice presented significantly ameliorated prostate tumorigenesis and tumor progression along with decreased body weight, protumorigenic cytokine secretion, and pan-amino acid synthesis when compared to TRAMP mice under the HF condition. This evidence concerns the gene FABP4 and medical procedure.