PDE4B and liver cancer: PDE4B promotes cancer progression in diffuse large B-cell lymphoma (Smith et al., 2005; Suhasini et al., 2016), colorectal cancer (Pleiman et al., 2018), breast cancer (Luo et al., 2021), lymphoid carcinoma (Nagy et al., 2013) and liver cancer (Ding et al., 2012; Sung et al., 2012), whereas in prostate cancer (Kashiwagi et al., 2012), down-regulation of PDE4B contributes to the occurrence and development of prostate cancer.