LncRNA MIR99AHG can act as a ceRNA to antagonize miR-136-5p-mediated down-regulation of USP4 expression, thereby deregulating miR-136-5p regulation of angiotensin-converting enzyme 2 (ACE2) expression and ultimately inhibiting the EMT process in lung fibrosis 210. The gene discussed is ACE2; the disease is pulmonary fibrosis.