ZBTB17 and chronic obstructive pulmonary disease: In addition, we recently reported that the downregulation of Miz1 by CS exposure or in COPD patients is attributed to the upregulation of the Miz1 E3 ubiquitin ligase Mule [Mcl-1 (myeloid cell leukemia 1) ubiquitin ligase E3; also known as Huwe1] (38).