FOXO1 downregulation contributes to the oncogenic program of primary mediastinal B-cell lymphoma.

Recently we have shown that the transcription factor FOXO1, highly expressed in B cells, is downregulated in classical Hodgkin lymphoma (cHL). As primary mediastinal B cell lymphoma (PMBL) has similarities with the cHL transcription program we investigated FOXO1 expression in this entity. By using immunohistochemistry we found that FOXO1 was absent or expressed at low levels in 19 of 20 primary PMBL cases.