These findings in AT2s are consistent with the known activation of the PERK/ATF4 pathway in ZZ-AATD circulating blood monocytes3 and in other AT2 protein misfolding diseases,29 in which it has been associated with the local elaboration of inflammatory cytokines and a fibrotic response to injury. The gene discussed is ATF4; the disease is alpha 1-antitrypsin deficiency.