ANGPTL4 and chronic obstructive pulmonary disease: In contrast to Li et al.’s results that cANGPTL4 expression level could not be detected by immunoblot analysis in the lung sample with obstructive pneumonia [27], it was reported that ANGPTL4 expression level in serum of patients with chronic obstructive pulmonary disease (COPD) was upregulated [46, 47].