FABP4 and obesity due to melanocortin 4 receptor deficiency: MAMs play key roles in steroid synthesis, phospholipid metabolism, and mitochondrial bioenergetics.[18] In both AAV‐FABP4 mice and PA treated USMCs, we observed wider distances between the ER and mitochondria compared to controls, suggesting that obesity or PA treatment impairs MAMs and related proteins (Figure 3F; Figure S1I, Supporting Information).