PDCD1 and neoplasm: Targeting simultaneously HER2 and PD-1 (margetuximab plus retifanlimab) or HER2 and PD-1 plus LAG-3 (margetuximab plus tebotelimab) enhances anti-tumour activity and the innate or adaptive immune response, with promising potential for patients with unresectable or metastatic GC/GEJC [28].