The murine primary KO99L cell line was established by cultivating tumoral thymocytes from a tPTEN-/- mouse. Mice carrying a T cell-specific deletion of PTEN develop invasive T-cell lymphomas and die within 10-15 weeks. KO99L cells display an abnormal constitutive activation of the PI3K/Akt/mTOR pathway that supports their enhanced proliferation and deregulated metabolism, as well as their resistance to cell death. This cell line also displayed an amplification of c-Myc .