CIBN(ΔNLS) corresponds to the N-terminal 170 amino acid residues encoded by the Arabidopsis thaliana CIB1 gene (TAIR:130033) in which the predicted nuclear localization signal normally found in this peptide sequence has been mutated so that it is non-functional (PMID:21037589). When exposed to blue light, the N-terminal photolyase homology region (PHR) of the Arabidopsis thaliana CRY2 gene (TAIR:28374) heterodimerizes with CIBN(ΔNLS), resulting in a heterodimer (PMID:18988809, PMID:21037589). This property can be used to bring together two tagged proteins of interest in vivo in a light-dependent manner, for example to reconstitute a functional protein by bringing together complementary split system components, or to target a protein of interest to a particular subcellular location.