Overlapping IGF2BP3 target genes from RIP-seq with differentially expressed genes between primary tumors and metastases in 3 MCC datasets (GSE39612, GSE22396, and GSE50451; Supplementary Tables S5–S7), we found 7 common genes, including ZMIZ2, ABHD2, FMNL3, TUG1, UBXN2B, MUC1 and LPCAT3. Six of these genes were previously identified as IGF2BP3-bound transcripts in other cell types (Supplementary Table S8). Here, IGF2BP3 is linked to Merkel cell skin cancer.