BRD2 and acute lymphoblastic leukemia: However, NAT (Fig. 2c) and ALL (Fig. 2a) are both significantly dry in 1982 (the year of the El Chichón eruption, near the driest observed year in 1984), and AA (Fig. 2b) and ALL both display multi-decadal variability in the second half of the century (including a partial recovery) which is characteristic of the observations and uncharacteristic of NAT and GHG (Fig. 2d).