Among the tests accomplished in patients with malignant pleural effusions are reinfusion with IL-2 of infiltrating lymphocytes and tumor infiltrates to the thoracic cavity with minimum toxicity.

Another advance is to make tumor cells more immunogenic by the transfer of costimulatory molecules like B7-1 & B7-2 that do not found in the tumors and are necessary for effective recognition of the tumoral antigens by the immune system.

Among the advantages gained by using this type of therapy is that antitumor protection is gained for a long time, nevertheless with certain difficulties like the unpredictable expression of costimulitory genes and tumor antigens like the loss of immune response.