To determine the effect of hyperactive STAT3 signaling and IL-6 on lung fibrosis, an elegant study was performed using transgenic mice containing a mutation in the common IL-6 family receptor subunit, gp130, leading to polarized and dysregulated STAT1/3 (gp130757F), or Erk1/2 (gp130ΔStat) signaling upon receptor activation (O’Donoghue et al., 2012). Here, IL6 is linked to pulmonary fibrosis.