For example, compounds that inhibit casein kinases led to period-lengthening effects in human osteosarcoma cells (U2OS) and mouse embryonic fibroblasts (MEFs)111, proposed to be linked to neuroprotective actions of CKI-δ encoded by CSNK1D. CKI directly acts on core-clock post-translational modifications by phosphorylation of PER23 pending to be validated further in vivo. The gene discussed is CSNK1D; the disease is osteosarcoma.