In the SMILE eyes, the concentration of substance P was significantly higher in the high myopia group compared to the low-moderate myopia group at 3 months (1977.20 ± 569.07 pg/mL vs. 1398.97 ± 315.79 pg/mL, P = 0.041) and no such significant difference was observed in the CLEAR eyes (Fig. 5d, e). Here, TAC1 is linked to myopia.