SF3B4 and breast cancer: The analysis showed that hnRNPK interacted specifically with intron 3 and 3′UTR of the IMPAD1‐201 pre‐mRNA, hnRNPD and IGF1BP1 interacted with BC and the 3′UTR of IMPAD1‐201, whereas hnRNPC, SF3B4 and RBM3 did not (Figure 4B).