Hi this study effectively combines precision genome editing, stem cell disease modeling, and advanced biochemistry, utilizing rigorous controls to guarantee reproducibility. However, incorporating specific methodological improvements could significantly strengthen the authors' conclusions. First, performing a phenotypic rescue by reintroducing PSEN2 into the knockout lines is recommended to confirm direct causality and rule out off-target effects or culture adaptations. Second, utilizing single-cell resolution tools (e.g., FACS or single-cell RNA-seq) would better address potential cell heterogeneity within the 100-day culture. Finally, because conclusions regarding endo-lysosomal dysfunction rely strictly on static protein measurements, complementing these findings with dynamic functional assays (such as Bafliomycin A1 treatment or enzymatic probes) is highly recommended to definitively assess autophagic flux and actual lysosomal degradation. Refining the biochemical resolution would also clarify key processing pathways. In Figure 2A, the accumulation of amyloid precursor protein fragments is generically labeled as "APP CTFs." However, the low-resolution band fails to discriminate between CTF/beta and CTF/alpha, leaving it unclear which pathway is affected by PSEN1-KO. Replacing conventional Western blotting with high-resolution Tricine-SDS-PAGE and using ImageJ to quantify the exact CTF/beta and CTF/alpha ratio would resolve this ambiguity. Similarly, in Figure 1F, the claim that Nicastrin is immature due to a lack of glycosylation is based solely on a downward band shift. To definitively prove this, treating wild-type samples with PNGase F or Endo H to align the bands would provide the necessary biochemical confirmation. Lastly, the discussion's interpretation of APP processing warrants caution. Asserting that PSEN2 does not alter Aβ generation is premature without quantifying the intracellular amyloid pool, especially given PSEN2’s endo-lysosomal localization. Furthermore, the proposed compensatory mechanism remains speculative, as an increase in PSEN2 could shift the Aβ42:40 ratio toward more pathogenic forms. Happy to discuss if needed. Best wishes.