Cyclic GMP-AMPs (cGAMPs) are new members of the cyclic dinucleotide family of second messenger signaling molecules identified in both bacteria and mammalian cells.A recent study by Gao et al.published in Cell Research has identified and characterized three 3'3'-cGAMP-spe-cific phosphodiesterases (termed as Ⅴ-cGAP1/2/3) in Ⅴ.cholerae,thereby providing mechanistic insights into the function of these enzymes that degrade cGAMPs.