After qRT‐PCR analysis, nine m6A‐tagged mRNAs (Smad4, Pik3cb, Brca1, Wnt5a, Dvl1, Vegfa, Fgfr1, Hif1a, and Stat6) associated with pluripotency‐ and tumorigenesis‐related signaling were highly accumulated in PCAT6‐deficient BC nuclei (Figure 2d), compared to those in control BC cells under hypoxia. Here, SMAD4 is linked to breast cancer.