At Bonferroni significance (P < 6.35 × 10−5), MR analysis revealed five protein–asthma pairs (Table 1, Figure 2), namely, interleukin 1 receptor type 1 (IL1R1), extracellular matrix protein 1 (ECM1), and a disintegrin and metalloprotease domain19 (ADAM19) in the plasma and PDZ and LIM domain 4 (PDLIM4) and ECM1 in the brain. This evidence concerns the gene IL1R1 and asthma.