GFAP and neoplasm: Similarly, a proportion of SHH-1A and SHH-1B cases showed positive staining for GFAP [7/22 (32%) and 3/12 (25%), respectively], whereas positive GFAP staining (> 5% of tumor cells) was not encountered in any SHH-2 examined [0/18 (0%); Chi-Square: 6.787; df: 2; P = 0.034].