TUSC2 and lung cancer: [11] They also observed loss or reduction of TUSC2 protein in 82% of non-small cell lung cancers (NSCLC). We detected very low levels of TUSC2 protein in pretreatment biopsies from both responding and non-responding patients. This observation and the overall high incidence of TUSC2 loss in lung cancer suggest that loss of TUSC2 protein expression alone may not be a predictive biomarker for TUSC2 gene therapy.