EGF and neoplasm: Lastly, given our data demonstrating an increase in the proportion of EGF(1,2,3,5) isoform among astrocytomas compared to normal human astrocytes, there is a possibility that this shift in expression patterns can be exploited for diagnostic purposes in certain clinical scenarios where there is uncertainty as to the identify of tissues, for example in differentiating possible recurrent tumor from normal adjacent brain with treatment effect.