70 ILCS 210/16
Members of the board shall hold office until their respective successors have been appointed and qualified. Any member may resign from his or her office, to take effect when his or her successor has been appointed and has qualified. The Governor and the Mayor of the City of Chicago, respectively, may remove any member of the Board appointed by him or her in case of incompetency, neglect of duty, or malfeasance in office, after service on him or her of a copy of the written charges against him or her and an opportunity to be publicly heard in person or by counsel in his or her own defense upon not less than ten days' notice. In case of failure to qualify within the time required, or of abandonment of his or her office, or in case of death, conviction of a felony or removal from office, his or her office shall become vacant. Vacancies shall be filled in the same manner as original appointments.
70 ILCS 210/16