Conversely, mitochondrial glutamate carrier 2 was found to be causally linked to ER− breast cancer as a risk factor (IVW, p=0.049, OR = 1.083, 95% CI: 1.000–1.174), alongside mitochondrial sodium/hydrogen exchanger 9B2 identified as a risk factor for ER− breast cancer (IVW, p=0.031, OR = 1.074, 95% CI: 1.006–1.145). Here, SLC25A18 is linked to breast cancer.