Table 1. Clinicopathologic and molecular features of CLDN18.2-positive or negative (cut-off: 2+, 40%) GC patients.

Characteristics	n (%)		P
	CLDN18.2-neg	CLDN18.2-pos
CLDN18.2, claudin 18 isoform 2; GC, gastric cancer; EGJ, gastroesophageal junction; HER2, epidermal growth factor receptor 2; IHC, immunohistochemistry; FISH, fluorescence in situ hybridization; amp, amplification; PD-L1, programmed death-ligand 1; CPS, combined positive score; EBV, Epstein-Barr virus; dMMR, mismatch repair-deficient; pMMR, mismatch repair-proficient; TMB, tumor mutational burden; muts, mutations; pos, positive; neg, negative.
Total	227 (42.4)	309 (57.6)
Age (year)
<60	128 (56.4)	236 (76.9)	<0.001
≥60	99 (43.6)	71 (23.1)
Sex
Female	58 (25.8)	140 (45.3)	<0.001
Male	167 (74.2)	169 (54.7)
Histopathology
EGJ	66 (29.6)	47 (15.6)	<0.001
Non-EGJ	157 (70.4)	254 (84.4)
Lauren
Diffuse	63 (36.4)	126 (47.7)	<0.001
Intestinal	78 (45.1)	70 (26.5)
Mixed	32 (18.5)	68 (25.8)
Differentiation
High	1 (0.5)	4 (1.4)	0.067
Moderate	50 (23.9)	47 (16.2)
Poor	158 (75.6)	239 (82.4)
Metastasis site
Liver	78 (30.6)	66 (17.4)	<0.001
Lung	26 (10.2)	25 (6.6)	0.102
Peritoneum	124 (48.6)	197 (52.0)	0.408
Uterine adnexa	16 (6.3)	74 (19.5)	<0.001
Lymph node	11 (4.3)	17 (4.5)	0.918
HER2 status
Negative	176 (84.2)	272 (93.2)	0.001
Positive	33 (15.8)	20 (6.8)
IHC 2+ FISH 　　amp	10 (30.2)	7 (35.0)	0.723
IHC 3+	23 (69.7)	13 (65.0)
PD-L1 status
CPS<1	100 (49.0)	187 (65.8)	0.001
CPS≥1	104 (51.0)	97 (34.2)
CPS<5	135 (66.2)	223 (78.5)	0.002
CPS≥5	69 (33.8)	61 (21.5)
CPS<10	155 (76.0)	246 (86.6)	0.002
CPS≥10	49 (24.0)	38 (13.4)
EBV status
Negative	168 (99.4)	235 (97.9)	0.217
Positive	1 (0.6)	5 (2.1)
MMR status
dMMR	3 (1.6)	4 (1.4)	0.921
pMMR	189 (98.4)	272 (98.6)
TMB (muts/Mb)
TMB<10	41 (77.4)	55 (83.3)	0.412
TMB≥10	12 (22.6)	11 (16.7)