Two pairs showed discordant MR effect sizes (Fig. 6A, B): (i) higher CSF ART (or AGRP, Agouti-related protein) was associated with higher levels of sodium in the urine, whereas higher plasma ART was associated with lower levels of the same trait; (ii) higher CSF TXD12 was associated with a higher risk of the ER-positive Breast cancer, whereas higher plasma TXD12 was associated with lower risk of the same phenotype. Here, AGRP is linked to breast cancer.