LRRN1 and cancer: Our previous studies have revealed that neuronal leucine-rich repeat 1 (NLRR1), a type І transmembrane protein, is associated with tumorigenesis by promoting cell proliferation through the activation of ERK mediated by EGF and IGF-1 (10) and negatively regulating anaplastic lymphoma kinase (ALK) (11) in NB, although the contribution of NLRR1 to other types of cancers is not understood.