However, since the total area positive for GFAP or cytokeratin was greater in pituitary tissue than in adenoma, the 2.6% of overlap equaled 44.70% of the area expressing cytokeratin and 46.77% of the GFAP positive area in adenoma, but only 15.68% vs. 24.13% of the area covered by intermediate filaments in pituitary tissue (p < 0.01 chi-square, see Table 4 in Supplement). Here, GFAP is linked to adenoma.