||Gene modulations in eukaryotes are very important for guiding the differentiation of cell types that are specialized to serve a particular function. Pre-messenger ribonucleic acid (mRNA)-splicing and microRNA processing, coupled with non-sense mediated decay are common strategies adopted to control gene expression. Cap-binding complexes, which have subunits ncbp-1 and ncbp-2, are implicated to be required in all of these events in plants to humans, which suggest that they play a conserved role in the determination of cell fate. Indeed, ncbp-1 and ncbp-2 have been found to determine the fate and identities of ray cells in Caenorhabditis elegans. I have demonstrated that by reducing the levels of either ncbp-1 or ncbp-2, this transforms the identity of ray 6 to that of ray 4, which results in rays 6-4 fusion. It has been confirmed that NCBP-1 and NCBP-2 co-localize at ray precursor cells and able to physically interact with each other via translational reporters and yeast-2-hybrid assays respectively. Therefore, it is suggested that they work together for ray patterning. In addition, ncbp-1/ncbp-2 is demonstrated to regulate ray identities by repressing Dbl/Sma signaling, rather than having a direct influence on the components of the pathway. ncbp-1/ncbp-2 is suggested to influence at the mRNA level, as it binds to the mRNA of dbl-1. This interaction is likely to be at the rays, and not at the ventral nerve cord. The findings of this study confirm the roles of ncbp-1 and ncbp-2 in cell fate determination, and inspire us on their possible mechanisms and targets.