In 1995, an ELISA to detect chromogranin A was developed specifically for diagnosis of neuroblastoma and a similar malignancy (phaeochromocytoma).297 It was found that 27% of neuroblastoma patients had normal levels of chromogranin A. Previous studies by Hsiao et al.298 suggested that chromogranin A was 91% sensitive for diagnosis of neuroblastoma; therefore, this ELISA test was not as sensitive as expected. This evidence concerns the gene CHGA and neuroblastoma.