Three families of AMPs—including penaeidins, crustins, and anti-lipopolysaccharide factors, possessing antibacterial, antifungal, and antiviral activities against different strains of bacteria, fungi, and viruses—are identified in shrimp; the expression of the AMPs are mainly regulated by the Toll and immune deficiency (IMD) and Janus kinase/signal transducers and activators of transcription (JAK/STAT) signal pathways [38,39]. The gene discussed is TLR4; the disease is Immunodeficiency.