ARCN1 and chronic obstructive pulmonary disease: In ADP2, expression of Coatomer subunit gamma-1 (COPG1) was decreased in response to oAβ (fold change 0.2, p = 0.028; Table 5), while its expression partner Coatomer subunit delta (COPD) was unchanged (fold change 1.2, p = 0.88; Table 1).