FABP4 and breast cancer: Regarding catabolite transporters, the expression of MCT1, CD36 and fatty acid transport protein-1 (FATP1) was detected in most breast cancer tissues with predominant localization proximal to adipose tissue, while the upregulated expression of MCT4 and CD36 and downregulated expression of fatty acid binding protein-4 (FABP4) were detected in most CAAs compared to normal mammary adipose tissue (Fig. 1a, Additional file 1: Figure S1).