Tamura et al. (2018) exposed transgenic mice (deficient in IL6R in SMCs) to chronic normobaric hypoxia and found that they exhibited decreased activation of STAT3 and expression of antiapoptotic proteins, such as MCL-1 and BCL2, in the lungs. Moreover, the mice showed decreased collagen deposition, inflammatory cell infiltration, and pulmonary hypertension (Tamura et al., 2018). Here, STAT3 is linked to pulmonary arterial hypertension.