In addition to the important role of the Pr1 protease in fungal infection, recent studies have shown that the acidic environmental hydrolase tripeptidyl peptidase (CLN2), belonging to the S53serine protease family, which is widely present in entomopathogens of Cordycipitaceae, plays a role in its pathogenicity in insects (the hemolymph of most insects is weakly acidic) (Wyatt et al., 1956; Stumpf et al., 2017; Lin et al., 2019). Here, TPP1 is linked to fungal infectious disease.