SPRY4 and Nephroblastoma: Considering IGF2BP2's affinity for mRNAs with high AU content [34, 35] we screened these downregulated mRNAs against published RBP CLIP-SEQ datasets, including Starbase [36], and CLIPdb [37], identifying six IGF2BP2-bound mRNAs, including SLC7A2, CKB, TSHZ2, NCKAP5, LIN28B and SPRY4. Given that circMARK2 promotes the progression of WT, LIN28B, which encodes a protein that has been mechanistically tied to Wilms tumor development [38], caught our attention.