XIST and glioblastoma: More importantly, XIST is directly associated with larger tumor size and overall shorter survival period.50 Human GBM cells transfected with a siRNA targeting XIST displayed diminished proliferation rate and increased sensitivity to TMZ as demonstrated by the BrdU and viability assay, respectively.51 RNA immunoprecipitation further showed that XIST affects the TMZ response by directly binding miR-29c and inhibiting its expression.