Similarly, in 7 studies conducted worldwide that included adults, MTHFR 1298 CC and AC polymorphisms were protective against CML (RR = 0.82, 95% CI [0.66, 1.01], p = .0421) while AA wildtype was a risk type for developing CML (worldwide, 7 studies: RR =1.14, 95% CI [1.00, 1.31], p = .0477; America, 3 studies: RR =1.18, 95% CI [1.01, 1.38], p = .0416) (Table 1B). Here, MTHFR is linked to chronic myelogenous leukemia, BCR-ABL1 positive.