Early in his presidency, Theodore Roosevelt sparked a scandal when he invited the African-American educator Booker T. Washington to dine with him and his family; he was the first president ever to entertain a black man in the White House. In 1886, Roosevelt ran unsuccessfully for mayor of New York City. Two years later, President Benjamin Harrison rewarded Rooseveltâs service to the Republican Party with a job on the U.S. Civil Service Commission; he was reappointed by Harrisonâs successor, Grover Cleveland.
1 Signaling involves a receptor, the transduction of information from the cell surface to inside the cell, and subcellular systems that make a response. 2  Receptors are proteins with specific binding sites for signaling molecules called ligands. All cells are equipped with elaborate systems for receiving signals from their environment. 2  The mechanisms involved in cell signaling are particularly crucial for understanding multi-cellular organisms, and are an important in many diseases.
Cell signaling is part of any communication process that governs basic activities of cells and coordinates all cell actions. The ability of cells to perceive and correctly respond to their microenvironment is the basis of development, tissue repair, and immunity, as well as normal tissue homeostasis. Errors in signaling interactions and cellular information processing are responsible for diseases such as cancer, autoimmunity, and diabetes. By understanding cell signaling, diseases may be treated