Lrp2, also known as megalin, is a representative of the phylogenetically conserved subfamily of giant LDL receptor-related proteins. It functions in endocytosis and is involved in the sonic hedgehog signaling pathway. It is crucial for embryonic development and adult tissue homeostasis, playing a role in the development of multiple tissues such as the brain, eye, heart, and kidney [1,2,3]. Genetic models like KO or CKO mouse models are valuable for studying Lrp2.

In gene-targeted mice lacking Lrp2 expression, there are significant consequences. In the ependyma, it fails to sort planar cell polarity (PCP) core proteins and NHERF1, an Lrp2 adaptor, leading to a loss of coordinated cilia arrangement and beating, highlighting its role in PCP-dependent cilia function [4]. In cardiac progenitor cells, Lrp2 deficiency causes premature differentiation of sonic hedgehog-dependent progenitor cells in the anterior second heart field, resulting in aberrant shortening of the outflow tract and conotruncal malformations [5].

In conclusion, Lrp2 is essential for endocytosis and the regulation of key signaling pathways during development. Studies using KO or CKO mouse models have revealed its critical roles in specific biological processes such as cilia function and cardiac development, contributing to our understanding of congenital diseases related to these processes.