NRAS and atrial fibrillation: In addition, BRAF mutation with AF‰ <1 can also coexist with NRAS G12/G13 mutation with both AF‰ ≥ 1 or AF‰ < 1, but the association with low AF‰ NRAS G12/G13 was much stronger (RR2 = 2.882 and RR3 = 2.400, Figure 1).