RRM2 and cancer: We further validated the PI3Kα activation signature by confirming that cancer cells isolated from peritoneal metastasis (two primary culture of patient‐derived cells) presented a significantly higher expression of FOXA1, RRM2, BIRC5, FGFR4, PHGDH, TYMS, as well as MYBL2, PTTG1, KIF2C, CDC20, CCNB1 albeit in a lower extent compared to non‐tumoural ductal cells (Appendix Fig S1B).