Enhances para sodium channel function. Required during pupal development to rescue adult paralysis and also protects adult flies against heat-induced lethality. Preferentially expressed in the central nervous system of developing embryos, weaker expression is seen in the peripheral nervous system. In pupae and adults, expression is seen predominantly in heads, body and legs. Expressed weakly in middle to late embryos, absent in larvae and is most abundantly expressed in middle to late pupal stages.