Moreover, by increasing epithelial pro-inflammatory signals, such as increased expression of the immune adhesion protein ICAM-1 and activation of ERK, X4 tropic HIV can have profound impact on initiating and maintaining local inflammation [42, 43] and causing tissue remodeling [44, 45], which are fundamental in the pathogenesis of COPD [46, 47]. The gene discussed is ICAM1; the disease is chronic obstructive pulmonary disease.