Additionally, in the case of HER2, the targeting of overexpressed or amplified HER2 receptors with trastuzumab produces an anti-tumor effect, in part through eliciting an increased adaptive and innate immune response [18], and there is preclinical evidence for synergy between anti-HER2 and anti-PD-1 therapy [19], as well as clinical evidence from other cancer types such as gastric adenocarcinoma [20]. Here, ERBB2 is linked to gastric adenocarcinoma.