Furthermore, the level of PTK2 pre-mRNA was reduced in BC cells when circRPAP2 was depleted or SRSF1 was overexpressed, whereas circRPAP2 overexpression or knockdown of SRSF1 caused intracellular accumulation of PTK2 pre-mRNA (Fig. 4E and F). The gene discussed is PTK2; the disease is breast cancer.