In this study, in vitro experiments demonstrated that ACSM5 inhibited FFA-induced FABP4/PPARγ signaling pathway activation in LF cells, and further in vivo animal experiments also indicated that overexpression of ACSM5 significantly inhibited the activation of FABP4/PPARγ signaling pathway in LF hypertrophy tissues. Here, ACSM5 is linked to Lassa fever.