KLK15 and neoplasm: Regarding lipid metabolism, in tumor samples from 6-week-old PyMTTg; MMP11Tg mice, we observed a significant increase in the expression of the fatty acid transporter Cd36 and the oxidative genes peroxisome proliferator-activated receptor alpha (Pparα) and its target gene acyl coenzyme A oxidase (Aco), but also increased expression of acetyl-Coenzyme A carboxylase 1 and 2 (Acc1 and Acc2), supporting an increased lipid uptake, utilization, and turnover (Figure 4Aa) [22,23,24].