Recently, Banerji et al. showed in a clinical study on ovarian cancer that a subset of patients who were treated with BCG945/CT400 (a novel alpha FR targeted TS inhibitor) and underwent pre- and post-treatment 18F-FLT PET scans had increases in 18F-FLT PET signals in the tumour tissue at 16–24 h post treatment, consistent with TS inhibition in tumour tissue [7]. The gene discussed is TYMS; the disease is neoplasm.