Background: T-type Ca2+ channels are often aberrantly expressed in different human cancers and participate in the regulation of cell cycle progression, proliferation and death.Methods: RT-PCR, Q-PCR, western blotting and whole-cell patch-clamp recording were employed to assess the expression of T-type Ca2+ channels in leukemia cell lines.The function of T-type Ca2+ channels in leukemia cell growth and the possible mechanism of the effect of T-type Ca2+ channel antagonists on cell proliferation and apoptosis were examined in T-lymphoma cell lines.