The voltage-sensitive sodium channel (VSSC) is essential for the generation and propagation of action potentials. The VSSC can change sodium kinetics by producing different splice variants (optional and mutually exclusive exons). The VSSC is the target site of pyrethroid insecticides as well as DDT and oxadiazines, which are used for control of crop pests and vectors of human diseases. Unfortunately, knockdown resistance (kdr) mutations in Vssc confer resistance to these insecticides. Recently, Silva and Scott 2019 investigated the conservation of VSSC by three approaches: (1) across insect Orders, (2) codon constraints of kdr mutations between populations of Aedes aegypti and (3) within a population of Drosophila melanogaster. Overall, VSSC is highly conserved across insects and within a population of an insect but important differences do exist. Read more: https://doi.org/10.1111/imb.12605