Spz1, mature peptide injection of which to the silkworm can significantly upregulate transcription of eight antimicrobial peptide genes (attacin 2, cecropin A1, -B1, -D1, gloverin A5, -B, lebocin-3, and moricin-A1), are highly expressed at the beginning of the infection and showed marked upregulation from 3 hpi to 48 hpi [99]. Here, SPZ1 is linked to infection.