Fig. 2.

Single-hit genetic inactivation causes loss of STAG2 in diverse human tumor types. (A) STAG2 sequence traces from TC-32 Ewing’s sarcoma cells derived from a female patient. Whereas the genomic DNA is heterozygous for a single nucleotide insertion (T), the mRNA is derived exclusively from the mutant allele on the active X chromosome. (B) Immunohistochemistry identifies frequent loss of STAG2 expression in glioblastoma and Ewing’s sarcoma primary tumors. Scale bar, 100 μm. (C) Number of tumors successfully assessed by immunohistochemistry and the fraction demonstrating complete loss of STAG2 expression.