During bacterial infections, the humoral defense mechanisms in silkworms involve the up-regulation of various PRRs such as PGRP-S1, PGRP-S2, PGRP-S3, PGRP-L1, PGRP-L3, βGRP3, and βGRP4, which respond to both Gram-positive and Gram-negative bacteria (Wang et al., 2021b, 2020a; Wu and Yi, 2018) (Figs. 1 and 2). This evidence concerns the gene PGLYRP1 and bacterial infectious disease.