MAP4K1 (Mitogen-Activated Protein Kinase Kinase Kinase Kinase 1): MAP4K1, also known as HPK1 (Hematopoietic Progenitor Kinase 1), is a member of the STE20 kinase family and plays a critical role in immune cell signaling. It is involved in the regulation of T cell activation and differentiation, acting upstream of the MAP kinase signaling pathway. MAP4K1's function in modulating immune responses makes it a potential target for immunotherapy, particularly in autoimmune diseases and cancer....