In various types of cancer, such as breast cancer (BRCA), cervical cancer (CESC), colon adenocarcinoma (COAD), head and neck squamous cell carcinoma (HNSC), lung adenocarcinoma (LUAD), lung squamous cell carcinoma (LUSC), skin cutaneous melanoma (SKCM), prostate adenocarcinoma (PRAD), thyroid cancer (THCA), and endometrioid cancer (UCEC), PPARG mRNA expression levels were significantly lower in cancerous tissues compared to paraneoplastic tissues. This evidence concerns the gene PPARG and invasive breast carcinoma.