Altor BioSciences aims to exploit the intrinsic selectivity of T-cell receptors (TCRs) by pairing soluble receptors with therapeutic payloads. These TCR/drug combos are smaller than antibodies and could theoretically bind to targets within cells, not just on the cell surface, a main selling point of the firm's so-called STAR technology. At first Altor plans to enhance the safety and efficacy of existing marketed drugs by pairing them with monoclonal antibody-like TCRs for improved targeting.