Non-Hodgkin's lymphoma (NHL) is present in about 1%–3% of HIV seropositive people at the time of the initial diagnosis of HIV. However, it is believed that such patients have been seropositive for a prolonged period, but have simply not had their infections recognized previously.[4] This is so because immunodysregulation must exist for an extended interval of time, in order for a lymphoproliferative process to evolve in that context.[4][5]