Class III HOMEODMAIN LEUCINE ZIPPER (HD-ZIPIII) genes play an essential role in ensuring plant leaves grow as flat structures optimised for photosynthesis. To better understand how these genes function, we recently identified two new closely related genes upregulated by REVOLUTA (REV) and repressed by the KANADI transcription factor, which acts antagonistically to the HD-ZIPIII genes. Interestingly, the newly identified genes encode transcription factors closely related to the KANADI family, thus named KANLIKE1(KANL1) and KANLIKE2(KANL2). KANL1 and KANL2 double mutant plants generated by CRISPR develop narrow curved leaves compared to wild-type ones, and this phenotype could be rescued by transforming the wild-type KANL1 gene into the double mutant, confirming the specificity of the CRISPR-generated phenotype. To investigate KANL genes further, we have begun analysing the expression patterns of genes known to be involved in leaf development in kanl mutants using confocal microscopy. We have found that WOX1 (WUSCHEL-RELATED HOMEOBOX family), which is involved in leaf lamina development, is ectopic in the double mutant. This suggests that the main function of KANL genes is to restrict the WOX1 expression. Further analysis will be presented.