The gene may play a role in Insect toxicity resistance. In culex mosquitos, it was one of several ribosomal proteins which were overexpressed in strains resistant to the insecticidedeltamethrin. More focused analysis revealed that resistant mosquitoes expressed RPL22 at a level more than 2.5x higher than susceptible strains; however, the same study found that over-expression of RPL22 in transfected cells caused a down-regulation of a different deltamethrin-resistance gene and made these cells overall less resistant to the insecticide.