MAP4K1 and chronic obstructive pulmonary disease: Furthermore, has_circ_0008672 sponges miR-1265 and regulates the downstream signaling molecule mitogen activated protein kinase 1 (MAPK1) and GO analysis predicted that has_circ_0008672 is at the core of three KEGG pathways (Nod-like receptor signaling pathway, natural killer cell mediated cytotoxicity and Th17 cell differentiation); dysregulated circRNAs are involved in biological and cellular processes, such as tolerance induction, cell death and apoptosis, MAPK kinase activation and signal transduction that can be associated with the pathogenesis of COPD.