Nonetheless, there was no apparent correlation between age and CD28 expression in the IPF cohort (rs = −0.1, p = 0.36), the overall age distributions of the comparison populations here were equivalent (Table 1), and both the number (n = 15) and proportion (19%) of octogenarians among CD28% High were actually greater than among the CD28% Low (n = 1 [9%]). The gene discussed is CD28; the disease is idiopathic pulmonary fibrosis.