CD8A and idiopathic pulmonary fibrosis: As CD8 was another histopathologic feature of IPF biopsies found to correlate with MRC in recent studies of our group [7], the correlation of tissue CD8 with both MRC scale and survival was examined with no statistically significant relationships found: (r = 0.154, p = 0.555, RR = 1.03, p = 0.42, 95% CI = 0.95-1.11, n = 17 respectively)