CA-170 is an oral small molecule peptide dual antagonist that selectively targets PD-L1 and VISTA. CA-170 has shown good safety and efficacy in the treatment of various types of tumors, including head and neck squamous cell carcinoma, NSCLC, MSI-H positive solid tumors, and Hodgkin’s lymphoma. Here, CD274 is linked to head and neck squamous cell carcinoma.