HILPDA and type 2 diabetes mellitus: We have not been able to use a mouse model of ABHD5 knockout as LDs are substantially smaller in mouse beta cells and glucose responsiveness of lipolysis was not clear in mouse islets.6,17 It also needs to be noted that PNPLA2 is also regulated by inhibitory cofactors such as HILPDA.10 It remains possible that upregulated HILPDA activity may account for dysregulated lipolysis and beta cell function in addition to ABHD5 dysfunction in T2D islets.