PIM1 and T-cell non-Hodgkin lymphoma: Several mouse strains have been used to study the proviral integration of M-MuLV; most of these studies have been carried out in the BALB/c and C57BL strains, but pim1 rearrangements were also observed in two T-cell lymphomas, one from an HRS/J mouse and one from a C58/J mouse.