TNF and atypical choroid plexus papilloma: CPT: choroid plexus tumors; IL: interleukin; TNF-α: tumor necrosis factor-alpha; TNF-γ: transforming necrosis factor-gamma; HIF-1α: hypoxia-inducible factor 1-alpha; HLA-DR: human leukocyte antigen-DR; CPP: choroid plexus papilloma; ACPP: atypical choroid plexus papilloma; CPC: choroid plexus carcinoma