HHLA2 and non-small cell lung carcinoma: Alternative immune evasion pathways using group III molecules of the B7-CD28 immune checkpoint family, which are B7x (B7-H4/B7S1), B7-H3 (CD276), and HHLA2 (B7H7/B7-H5/B7y), are expressed in 60–90% of NSCLC patients [30,31,32].