FAS and lymphedema: Other factors likely to operate include local entrapment of lymphocytes in the lymphoedematous limb, upregulation of apoptosis induced by increased Fas (CD95) levels, as described in IL,12 disordered lymphopoiesis/thymic atrophy,13 and disordered interactions between the lymphoid cells and the lymphatic endothelial cells.10 The interaction between systemic immunodeficiency and lymphoedema is likely to be bidirectional and complex.