An RNAseq analysis in that same study identified transglutaminases as being more highly expressed in the heart containing periostial hemocytes than in other tissues [26], and follow-up experiments confirmed that TGase3—but not TGase1 or TGase2—is a negative regulator of periostial hemocyte aggregation during the early stages of infection, presumably by inhibiting the IMD pathway [19]. Here, TGM2 is linked to infection.