The ideal cancer target antigen (Ag) is expressed at high copy numbers on neoplastic cells, absent on normal tissues, and contributes to the survival of cancer cells. Despite significant investments in the identification of cell surface Ags, there is a paucity of targets that meet such ideal cancer target criteria. Recent clinical trials in patients with cancer treated with immune checkpoint inhibitors (ICIs) indicate that cluster of differentiation (CD)8⁺ T cells, by means of their T cell receptors (TCRs) recognizing intracellular targets presented as peptides in the context of human leukocyte antigen (peptide–human leukocyte antigen complex; pHLA) molecules on tumor cells, can mediate deep and long-lasting antitumor responses in patients with solid tumors. Therefore, pHLA-target Ags may represent the long sought-after, ideal targets for solid tumor targeting by high-potency oncology compounds.

理想的癌症靶抗原（Ag）在肿瘤细胞上以高拷贝数表达，在正常组织中不存在，并且有助于癌细胞的存活。尽管在识别细胞表面Ags方面进行了大量投资，但仍缺乏满足此类理想癌症靶标标准的靶标。最近用免疫检查点抑制剂（ICI）治疗的癌症患者的临床试验表明，分化簇（CD）8 ⁺T细胞通过其T细胞受体（TCR）识别肿瘤细胞上人白细胞抗原（肽-人白细胞抗原复合物； pHLA）分子中呈肽形式存在的细胞内靶标，可以介导深层和长期的抗肿瘤反应在实体瘤患者中。因此，pHLA靶向Ags可能代表了长期以来人们寻求的，通过高效肿瘤学化合物靶向实体瘤的理想靶标。