PTEN and acute lymphoblastic leukemia: Miething et al. [51] exploited a transgenic mouse model where Pten expression in HSCs was regulated in both a time- and tissue-specific manner, to show that PTEN loss in the postnatal period sensitized T-ALL cells to C-C chemokine ligand 25 (CCL25), which is mainly expressed in mucosal epithelial cells in the small intestine.