Table 5. Univariate analysis of associations between single-nucleotide polymorphisms (SNPs) and grade ≥ 3 radiation pneumonitis.

SNPs	Training Cohort			Validation Cohort			Pooled analysis
BMP2	HR	95% CI	P	HR	95% CI	P	HR	95% CI	P
rs170986 (CA/CC vs. AA)	0.345	0.107–1.11	0.074	1.484	0.202–10.905	0.698	0.691	0.253–1.891	0.472
rs1979855 (AG/AA vs. GG)	0.870	0.120–6.316	0.890	0.680	0.092–5.005	0.705	0.818	0.201–3.335	0.779
rs1980499 (CT/TT vs. CC)	1.640	0.768–3.505	0.201	1.047	0.443–2.477	1.047	1.390	0.790–2.448	0.254
rs235768 (AT/TT vs. AA)	1.957	0.703–5.449	0.199	1.104	0.421–2.893	0.841	1.534	0.765–3.075	0.228
rs3178250 (CT/TT vs. CC)	0.272	0.108–0.687	0.006	0.524	0.071–3.870	0.524	0.303	0.132–0.698	0.005
BMP4
rs17563 (AG/GG vs. AA)	0.806	0.434–1.499	0.496	2.452	0.853–7.048	0.096	1.182	0.698–2.001	0.535
rs4898820 (GT/TT vs. GG)	1.761	0.748–4.148	0.195	0.926	0.377–2.276	0.926	0.332	1.357–2.514	0.332
rs762642 (AC/CC vs. AA)	2.176	0.780–6.068	0.137	1.073	0.373–3.084	0.896	1.614	0.775–3.360	0.201

Abbreviation: HR, hazard ratio; CI, confidence interval.