CRY2(FL-ΔNLS) corresponds to the full-length Arabidopsis thaliana CRY2 gene (TAIR:28374), in which the nuclear localization signal has been mutated so that it is non-functional (PMID:21037589). When exposed to blue light, CRY2(FL-ΔNLS) heterodimerizes with the N-terminal domain of the protein encoded by the Arabidopsis thaliana CIB1 gene (TAIR:130033), 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.