At the same time, some research demonstrates its increased expression in some types of oncological diseases (non-small cell lung cancer, breast cancer, Waldenstrom’s macroglobulinemia, hepatocellular carcinoma and colorectal cancer) [158,159,160], whereas other investigations reveal reduced levels of SIRT5 (endometrial carcinoma, head and neck squamous cell carcinoma and hepatocellular carcinoma) [161,162]. This evidence concerns the gene SIRT5 and breast cancer.