CCND1 and breast cancer: Previous studies in human breast cancer cell lines (MCF-7, ZR-75-1, T47D, MDA-MB-231, MDA-MB-468, and SK-BR3) have shown that treatment with CBD delivered in DMSO induces G0-G1 arrest through CB1 receptor activation, leading to downregulation of cyclin D1 [55,59,60].