FABP4 and obesity due to melanocortin 4 receptor deficiency: Of interest, Hao and co-workers used human samples and mouse models to show that (i) increased circulating A-FABP levels were found in obese patients with breast cancer; (ii) circulating A-FABP induced breast cancer aggressiveness in both in vitro and in mouse models; (iii) A-FABP promoted breast cancer stemness through the IL6/STAT3/ALDH1 signaling pathway; (iv) A-FABP ablation decreased obesity-associated breast cancer growth in different mouse models [20].