PTPRF and chronic obstructive pulmonary disease: In our analysis, FUZ expression was also positively correlated ACVR1B and PTPRF and inversely correlated with FASTKD3. ACVR1B, part of the transforming growth factor-beta family, has established associations with COPD pathogenesis, as an identified expression quantitative trait loci in COPD blood, sputum, and lung [35, 36] and as a causal gene in emphysema distribution [37].