S100A8 and lung carcinoma: The stimulation of NPTNβ on lung cancer cells with S100A8/A9 leads to an invasive event in the lung via the activation cascade of nuclear factor I (NFI)A/NFIB and SAM pointed domain-containing ETS transcription factor (SPDEF) with the help of two adaptor proteins: tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2) and growth factor receptor-bound protein 2 (GRB2) [15].