KIT and gastrointestinal stromal tumor: As shown in Figure 2G and Figure S5, 5 residues (ARG353, GLY470, ASN406, GLU435, and ASN463) of KIT bind with 5 bases of KIT-d (A18, G20, G21, G24, and A29), and these bases are consistent with the stem-loop structure depicted in Figure 2F. Subsequently, we introduced mutations into the stem-loop structure of KIT-d, which is predicted to interact with the KIT protein, as shown in Figure 2F. The mutated versions, KIT-d-mu1, KIT-d-mu2 and KIT-d-mu3, exhibited significantly reduced binding ability for GIST cells (Figure S6).