Though conceptually understood for decades, antibody-drug conjugates (ADCs) haven’t begun to come into their own until recently, but oncology drug developers continue to wrestle with challenges, large among them the problem of antigen selection. Lately, companies including names such as Adagene Inc., Bioatla Inc. and Cytomx Therapeutics Inc., have taken particular interest in exploiting features of the cancer growth itself to add more oomph, with focus on special features of the tumor microenvironment (TME).