DHFR and cancer: Taking into account that CK2 regulates many oncogenic pathways and processes, we have recently undertaken the studies on simultaneous treatment of cancer cells with inhibitors of TS and CK2 (Wińska et al., 2018; Wińska et al., 2020) or DHFR and CK2 (Wińska et al., 2019) searching for the synergistic effect.