CSTF2 (cleavage stimulation factor 2), an important modulator of the cleavage stimulation factor complex which regulates APA is in the bottom left-hand corner and has the most negative Euclidean distance in Fig 2B, such that its differential expression in COPD will also contribute to less distal SERPINA1 mRNA expression. Here, CSTF2 is linked to chronic obstructive pulmonary disease.