HHIP and pulmonary emphysema: In contrast, compared to wild-type control, HHIP haploinsufficient mice exposed to cigarette smoke exhibit activation of lymphocytic pathways, increased activation of TCD8 cells (Lao et al., 2015), and more severe emphysema, suggesting that HHIP protects lung cells from environmental stressors, such as oxidative stress (Lao et al., 2016).