Suggested hypothesis of Chi3l1 roles in anti-tumoral T-cell immunity. Chi3l1 expression is induced by TcR or IL-4 stimuli in T cells. Chi3l1 might strengthen Th1 inhibitory genes, such as socs1 and twist1, to regulate IFNγ sensitivity in Th1 and CTL. Thus, targeted knockdown of Chi3l1 by dNP2-siChi3l1 elicits Th1 and CTL functions and inhibits tumor growth and metastasis in vivo.