In addition to matching the temporal sequence of clinical lymphedema, the Cre-Lox model also mimics the human disease histologically and radiographically, as the initial resolution of the edema correlates with the infiltration of M2-polarized macrophages, whereas the subsequent accumulation of CD4+ cells results in impaired lymphangiogenesis, collecting fibrosis, and lymphatic smooth muscle cell proliferation associated with lymphedema. The gene discussed is CD4; the disease is lymphedema.