The role of the FoxO signaling pathway has already been documented in fish; this pathway was enriched in both spleen and head kidney of largemouth bass (Micropterus salmoides) after infection by Aeromonas hydrophila, with phosphatidylinositol 3-kinase (pik3r3b) and serine/threonine-protein kinase (plk2) being among four target genes. The gene discussed is PLK2; the disease is infection.