MAP2K4 and infection: In agreement with previous reports45, susceptibility to PA14 infection was elevated in the presumed null mutants pmk-1(km25)(pmk-1(−)) and sek-1(km4)(sek-1(−)), with sek-1(−) mutants exhibiting more severe defects than pmk-1(–) animals (Fig. 5g and Supplementary Table 1).