PIK3CB and breast cancer: We performed a comprehensive analysis of nuclear/cytoplasmic RNA‐seq data and meRIP‐seq data from PCAT6 knockdown and control BC cells and identified 174 m6A‐modified mRNAs that clustered in the nuclear of PCAT6 knockdown Hs578T (Figure S2i, Supporting Information), in which pluripotency‐ and tumorigenesis‐related signaling pathways (e.g., Wnt, PI3K‐AKT, and pluripotency of stem cell regulatory signaling) were significantly enriched (Figure S2j, Supporting Information).