According to experimental data, ICT1 knockdown causes an increase in the amount of p21 and a decrease in the amount of cyclin D1 in lung cancer (Wang et al., 2017a), a decrease in the amount of CDK1, CDK2 and cyclin B1 in breast cancer (Chen et al., 2017), a decrease in the amount of cyclins A2 and B1 in gastric cancer (Wang et al., 2017b), a decrease in the amount of CDK1 and cyclin B1 in hepatocellular carcinoma (Chang et al., 2017), a decrease in the amount of cyclin A2 and an increase in p21 in leukemia (Li et al., 2018). The gene discussed is CCNA2; the disease is breast cancer.