TNF and colorectal neoplasm: Single cell suspensions from normal adjacent tissue and colorectal tumor tissue were prepared from fresh surgical explants and stimulated for 3.5 h with PMA and ionomycin in the presence of brefeldin A. Cells were then stained with antibodies specific for T cell markers, permeabilized, and incubated with antibodies specific for the following cytokines: IFN-γ, IL-17A, TNF-α, IL-2, and IL-10.