Open AccessdWarts is a NDR kinase that plays a key role in the regulation of cell proliferation and apoptosis. Loss of function of dwarts caused cell over-proliferation and cancer. In this study, one of regulatory mechanisms of dwarts was reported. Similar to human Lat1, the insertion segment of dwarts in the catalytic domain was identified as negative regulatory domain, as multiple mutations in the insertion segment by substituting the conserved alkaline amino acids resulted in the enhanced small compound eye phenotypes when expressed in the eye discs of Drosophila. Moreover, our results demonstrated that regardless of identical genetic background, both wild type dwarts and mutant dwarts could confer incomplete penetrance phenotype when ectopically expressed in the eye discs of transgenic Drosophila, suggesting multiple regulatory mechanisms may be associated with dwarts.