Recent developments in our understanding of lymphocyte receptor-associated signalling events have offered many new potential targets for modifying antigen and cytokine receptor signalling events in immune-related diseases such as allergy, autoimmunity and transplant rejection. As discussed below, these targets are largely tissue-restricted and are functionally confined to a limited set of receptors. Therefore, it is anticipated that selective inhibitors of these signalling events would offer safe and effective therapies for immunologically-based diseases. First, we review T and B cell antigen receptor signalling as targets for inhibiting lymphocyte responses. Second, targets in lymphocyte cytokine receptor signalling pathways are discussed. Finally, we review strategies for inhibition of receptor signalling.