please rewrite the following text in the tone of the discussion of a Cell paper. Please keep all the information and add more information if necessary: 'This study has some limitations. 
We isolate the wavefront ENCCs based on their location and their molecular properties. but the transcriptional differences between wavefront ENCCs and other bipotent cells are small. This classification may not be accurate. though the properties meet the requirement and we verified a few of the markers. 
Although we have provided a good gene expression resource of developing  ENCCs, and we have validated several gene expression patterns by immunostaining, further works on examining the expression of other key molecular markers may offer more valuable information in the field. In addition, functional studies are required to verify whether the marker genes are critical to the proliferation, migration and differentiation of the wavefront ENCCs. 
Second, some findings of the TFs, cell-cell interaction proteins, and signaling pathways during the ENCC migration and colonizatoin were reported only based on transcriptomic data; further work exploring novel molecules and validating these molecules and signaling pathways in humans will be required. In future work, it will be important to experimentally validate the functional roles of these genes. 
Spatial transcriptional data is only a correlation. Whether the gene expression is caused by the arrival of wavefront ENCCs has to be examined using Ednrb-/- mutant mice. 
'  I want the entire output in JSON format.
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