The overexpression of receptor tyrosine kinases (RTKs) has been correlated with the progression and poor survival of GC, whereas the immuno-histochemical overexpression of RTKs variant (i.e., human epidermal growth factor receptor 2—HER2) was found to be associated more frequently in the development of IGC rather than DGC [96,97,98]. This evidence concerns the gene ERBB2 and gastric cancer.