In this issue of the Journal, two reports present data on the efficacy of two new biologic drugs for psoriasis. One of these drugs, etanercept, has been used extensively in rheumatology and targets the pleiotropic inflammatory cytokine tumor necrosis factor α (TNF-α). The other, efalizumab, targets CD11a, or α_L, one chain of α_{L β2} integrin, also known as leukocyte-function–associated antigen 1 (LFA-1); LFA-1 is important in the process by which T cells cross blood-vessel walls, enter tissue, and are subsequently activated by antigen. Increasingly, molecules that were once the exclusive domain of immunologic scientists have entered mainstream . . .