Table 3. TCGA Subtypes.

Subtypes	EBV-positive	MSI	GS	CIN
Frequency	8.8%	21.7%	19.7%	49.8%
Demographic	Male patients (81%)	Old age (median 72 years)	Young age (median 59 years)	No special
Histology			Diffuse histology	Intestinal histology
Main location	Fundus or body (62%)			Gastro-esophageal junction/cardia (65%)
Molecular alterations	EBV-CpG island methylator phenotype (CIMP)	Gastric-CIMP	CDH1, RHOA mutation	TP53 mutation
	PD-L1/2, JAK2 overexpression	Hypermutation in TP53, PIK3CA, ERBB3, ARID1A	CLDN18-ARHGAP fusion	RTK-RAS activation
	Mutation in PIK3CA, ARID1A, BCOR	MLH1 silencing	Cell adhesion, angiogenesis pathways enriched	Mutations of SMAD4 and APC
	CDKN2A silencing	Mitotic pathways activation	Rare TP53 mutations
	Immune cell signaling	Commune changes in the genes of CMHI
	Rare TP53 mutations
Potential targets	PIK3CA, JAK2, PD-L1/PD-L2	PIK3CA, ERBB2/3, EGFR, PD-L1, MLH1 silencing	RHOA, CLDN18	RTKs, EGFR, VEGFA, CCNE1, CCND1, CDK6
Treatment reaction		No respond to adjuvant chemotherapy

ARID1A: AT-rich interactive domain-containing protein 1A; BCOR: B-cell lymphoma 6 corepressor; CIN: chromosomal instability; GS: genomically stable; GC: gastric cancer; CIMP: CpG island methylator phenotype; DNMT3b: DNA methyltransferase 3b; EBV: Epstein-Barr virus; EGFR: epithelial growth factor receptor; ERBB2: Erb-B2 receptor tyrosine kinase 2; JAK2: Janus-associated kinase 2; LMP2A: latent membrane protein 2A; LELC: lymphoepithelioma-like carcinoma; MSI: microsatellite instability; PI3K: phosphatidylinositol-3-kinase; RHOA: Ras homolog family member A; TCGA: The Cancer Genome Atlas; PD-L1/2: programmed death ligand-1/2; CDK6: cell division protein kinase 6.