Table 3. Heterogeneity tests.

Cancer	Method	Q	Q_df	P value
Lung cancer	MR-Egger	22.379	12	0.033*
	Inverse variance weighted	23.229	13	0.039*
Small cell lung cancer	MR-Egger	10.322	12	0.588
	Inverse variance weighted	10.414	13	0.660
Lung adenocarcinoma	MR-Egger	12.042	12	0.442
	Inverse variance weighted	12.148	13	0.516
Squamous cell lung cancer	MR-Egger	14.548	12	0.267
	Inverse variance weighted	16.411	13	0.228

*, P value <0.05. MR, Mendelian randomization.