GFAP and nasopharyngeal carcinoma: We also treated NPC with freshly prepared mouse serum, which in high concentrations induced a comparable phenotype to FBS, including reduction in Gfap expression, increased cytoplasm and nuclei size, flattened morphology, and increased arrangement of actin stress fibers (Supplementary Figs. 5j and 6i), ruling out non-specific effects of FBS.