805 ILCS 305/3

A professional association may adopt a name consisting of the full or last name of one or more of the associates, followed by the term "associated" or "association" or "and associates" or the abbreviation "assoc." Nothing in this Act shall be construed as affecting "An Act in relation to the use of an assumed name in the conduct or transaction of business in this State", approved July 17, 1941, as heretofore or hereafter amended.