Although no one has actually assessed RPE development in Mfrp mutants, apical microvilli defects have been reported. It is interesting to note that during normal eye development, there is a specific and strong increase in Rpe65 transcription that coincides with the extension of RPE microvilli and the increase in the photoreceptor OS length. Thus, the decrease in Rpe65 transcript observed in Mfrprd6 mice may contribute to the decrease in OS length and organization. Moreover, in Mfrprd6 mutants, the significant decrease in transcripts of Fscn2, encoding a protein involved in outer DAPT segment morphogenesis, may contribute to the failure to elaborate OS and to the disorganization of OS, followed by photoreceptor degeneration similar to that observed in the Fscn2 haploinsufficient mouse model. In summary, although we do not know currently how MFRP mediates its effects on the visual cycle and phototransduction genes, it is likely that the observed reductions play a role in the pathogenesis of the disease induced by disruptions in Mfrp. Moreover, two different genome-wide association studies involving multi-ethnic cohorts identified Prss56 as significantly associated with refractive errors and myopia that relate to a change in axial length. MFRP mutations in humans are also associated with posterior microphthalmia characterized by abnormal posterior segment size leading to hyperopia and cause recessive nanophthalmos. Studies on the postnatal progression of refractive error in nanophthalmos patients having mutations in MFRP suggest a role of MFRP protein in embryonic ocular growth and postnatal emmetropization. As both PRSS56 and MFRP variants affect axial length and potentially the process of emmetropization, it is plausible that they may function through a common biological pathway, yet to be determined. Plants use pattern-recognition receptors as a first layer of defense against pathogens. In order to engineer plants with improved pathogen recognition abilities, it is important to understand the molecular details underlying the interaction of PRRs not only with their ligands but also with their co-receptors, immediate downstream targets and other partner proteins that facilitate appropriate signaling. Several PRRs have been identified in different plant species. PRRs are localized at the plasma membrane where they monitor the apoplastic space for microbe-associated molecular patterns, damage-associated molecular patterns and apoplastic effectors. Most known PRRs are receptor-like kinases or receptor-like proteins. Both receptor types consist of an extracellular domain for ligand perception and a transmembrane domain, but only the RLKs have an intracellular kinase domain. Two of the best characterized PRRs, FLS2 and EFR, carry large extracellular domains that predominantly consist of a leucine-rich repeat domain. The genomes of Arabidopsis and other plants each encode hundreds of LRR receptor-like kinases.