SHIP-deficient CD4 T cells polarize in culture but have decreased Th2 cytokine production. CD4cre SHIPfl/fl (dark bars) and SHIPfl/fl (light bars) CD4+ T cells were stimulated with anti-CD3 plus anti-CD28 under Th1 (A), Th2 (B), or Th0 (C) polarizing conditions for 3 days, expanded in IL2 for 4 days, and restimulated with anti-CD3 plus anti-CD28. Supernatants were collected 24 h after restimulation and cytokine expression assessed by the CBA Assay. ∗, P < 0.05.