N-iodoacetyl-N'-(5-sulfonic-1-naphthyl)ethylene-diamine modified autologous cells are shown to induce respective high and low AED-self CTL responses by spleen cells from H-2b and H-2k mice. The lysis mediated by effector populations from both haplotypes was highly H-2 restricted. Cytotoxic responses induced by a 2nd sulfhydryl- (SH) specific reagent, dithionitrobenzoic acid (DTNB), were shown not to be cross-reactive at the effector cell level with AED-self but exhibited the same high and low CTL response patterns as those induced against AED-self. These Ir-effects reported for the 2 SH reactive compounds are discussed in relation to the opposite Ir-patterns demonstrated against a number of amino (NH2) reactive compounds. The difference of self-recognition sites is suggested to account for the contrasting results observed in the response patterns induced by SH- and NH2-reactive compounds. The AED-self CTL response was found to exhibit Kk-self over Db-self Ir regulation. Thus, this latter type of genetic control appears to function independently of whether the hapten is an SH- or NH2-reactive compound.