FIGURE 1.

. Flowchart and study design of TSMR and TWAS. SNPs from publicly available GWAS data sets were selected as IVs based on their strong correlation with the exposure and independence from confounding factors. These IVs were required to influence the outcome solely through exposure, ensuring the credibility of the MR analysis. Furthermore, the GWAS data were converted into TWAS format to identify gene transcripts associated with air pollutants and ALS. The figure was created by Biorender.com. GWAS, genome‐wide association study; IVs, instrumental variants; SNP, single nucleotide polymorphism; TSMR, two‐sample Mendelian randomization; TWAS, transcriptome‐wide association.