Abstract
The proto-oncogene Myc is already known to affect many cellular processes, but recent experiments in the fruit fly Drosophila melanogaster have revealed yet a new facet of Myc. Neighboring cells were shown to compare their Myc levels and the losers (cells with lower Myc activity) were actively eliminated. This phenomenon is called "cell competition," and it seems to be part of a developmental size and quality control program. Subversion of this mechanism may contribute to the transforming powers of Myc and possibly other oncogenes.