ERBB2 and gonorrhea: Some of the most significant targets for GC are: HER2, MUC1, and CEA, as well as other targets, such as mesothelin, epithelial cell adhesion molecule (EpCAM), folate receptor 1 (FOLR1), claudin 18.2 (CLDN 18.2), and natural-killer receptor group 2, member D (NKG2D).