STEAP1 and pachyonychia congenita: To design ADCs for combination mCRPC therapy with improved efficacy and specificity, we first analyzed the distribution of clinically relevant PC targets: prostate specific membrane antigen (PSMA, FOLH1) (9,10), six-transmembrane epithelial antigen of prostate-1 (STEAP1) (11,12), and B7 homolog 3 (B7-H3, CD276) (13-15) in mCRPC and normal tissues and proposed to use these antigens in pairs for dual ADC targeting.