Table 7.

MR results of the causal effect of ER-negative BC on MMP-3.

Exposure	Outcome	No. of SNPs	Method	β	P value	Heterogeneity		Pleiotropy
						Cochrane's Q	P	P
ER-negative BC (ieu-a-1128)	MMP3	37	MR Egger	− 0.12	0.07	52.17	0.03	0.04
			Weighted median	− 0.005	0.86
			Inverse variance weighted	0.002	0.95	58.61	0.01
			Simple mode	− 0.05	0.35
			Weighted mode	− 0.02	0.52
ER-negative BC (ieu-a-1135)	MMP3	14	MR Egger	− 0.11	0.15	9.64	0.65	0.20
			Weighted median	− 0.008	0.81
			Inverse variance weighted	− 0.02	0.45	11.51	0.57
			Simple mode	0.02	0.64
			Weighted mode	0.002	0.97
ER-negative BC (ieu-a-1136)	MMP3	7	MR Egger	− 0.07	0.64	2.14	0.83	0.61
			Weighted median	− 0.007	0.86
			Inverse variance weighted	0.006	0.84	2.44	0.88
			Simple mode	− 0.02	0.78
			Weighted mode	− 0.01	0.83
ER-negative BC (ieu-a-1166)	MMP3	8	MR Egger	− 0.35	0.12	2.18	0.90	0.11
			Weighted median	− 0.01	0.76
			Inverse variance weighted	0.004	0.88	5.70	0.57
			Simple mode	− 0.01	0.83
			Weighted mode	− 0.01	0.83

BC Breast cancer; ER Estrogen receptor; MMP Matrix metalloproteinases; MR Mendelian randomization; SNP Single nucleotide polymorphisms.