STIP1 and central nervous system cancer: Additionally, Stress-Inducible Phosphoprotein 1 (STIP1), abundantly present in glioma cells, and Stress-Inducible Protein 1 (STI1), released by microglia, significantly contribute to the progression of glioblastoma multiforme, with their expression levels positively associated with the degree of tumor malignancy (173).