CD28 and small cell lung carcinoma: The top ten pathways included CD28 signaling in T cells, phosphoinositide 3-kinase (PI3K) signaling in B lymphocytes, the role of nuclear factor of activated T cells (NFAT) in regulation of immune responses, phospholipase C signaling, B cell receptor signaling, leukocyte extravasation signaling, integrin signaling, protein kinase C (PKC) zeta signaling in T lymphocytes, inducible T cell costimulator- (ICOS-) inducible T cell costimulator ligand (ICOSL) signaling in T helper cells, and non-small-cell lung cancer signaling.