CSNK1A1 (casein kinase 1 alpha 1) is a serine/threonine protein kinase that functions as a multifunctional regulator of cellular signaling and autophagy. As a casein kinase, CSNK1A1 phosphorylates diverse protein substrates and participates in Wnt signaling by phosphorylating CTNNB1 at serine-45 1. Beyond canonical Wnt regulation, CSNK1A1 serves critical roles in immune homeostasis and autophagy: it suppresses autoimmunity by promoting autophagic degradation of STING1 through phosphorylation of SQSTM1/p62, thereby restraining cGAS-STING1 signaling and type I interferon production 2. CSNK1A1 also regulates autophagosome maturation by phosphorylating UVRAG at serine-522, disrupting its interaction with SMURF1 and modulating autophagy flux 3. Disease relevance extends to hematologic malignancies: haploinsufficiency of Csnk1a1 cooperates with p53 loss to promote acute leukemic transformation through MAPK and Myc upregulation in del(5q) myelodysplastic syndrome 4. In hepatocellular carcinoma, ITGB5 upregulates CSNK1A1, which phosphorylates ITGB5 to enhance EGFR signaling and confer sorafenib resistance 5. Additionally, CSNK1A1 deletion drives WNT-dependent intestinal tumorigenesis 6. CSNK1A1 mutations occur frequently in adult T-cell leukemia/lymphoma associated with HTLV-1 infection 7. Pharmacological modulation of CSNK1A1 through selective agonists or inhibitors represents a therapeutic strategy for autoimmune diseases and hematologic malignancies.