In contrast, solid tumors remain difficult to treat due to heterogeneous antigen expression and an immunosuppressive tumor microenvironment that fosters immune evasion and is driven to a large part by checkpoint-mediated inhibition.<h4>Methods</h4>To overcome these barriers, we engineered novel dual CAR-NK cells targeting the immune checkpoint PD-L1 and the tumor-associated antigen ErbB2 (HER2). Here, CD274 is linked to neoplasm.