1.

Baseline characteristics of the study population

Variables	All patients	PD-L1 positive	PD-L1 negative	P
pTNM, pathological TNM; TILs, tumor infiltrating lymphocytes.
Total	73	19	54
Age at diagnosis, years				0.570
< 65	46	13	33
≥ 65	27	6	21
Gender				0.297
Male	31	10	21
Female	42	9	33
Smoking history				0.429
Never-smoker	44	10	34
Former/current smoker	29	9	20
Pathological classification				0.973
Adenocarcinoma	71	18	53
Non-adenocarcinoma	2	1	1
pTNM stage				0.591
pI-IIIA	69	17	52
pIIIB-IV	4	2	2
Lymph node metastasis				0.661
Yes	30	7	23
No	43	12	31
KRAS mutation				0.020
KRAS mutation	3	3	0
KRAS wild type	70	16	54
CD8+ TILs expression				0.056
Yes	22	9	13
No	51	10	41