In addition, pathway enrichment analysis showed that particular pathways that were activated in specific groups (e.g., lysine degradation in pre-treatment HER2-positive gastric cancer compared with HER2-negative cancer; spliceosome and nucleotide excision repair pathways in the post-treatment HER2-positive gastric cancer compared with pre-treatment HER2-positive gastric cancer). The gene discussed is ERBB2; the disease is cancer.