SSKI (Saturated Solution of Potassium Iodide) is an antimicrobial agent with widespread clinical applications that go beyond the treatment of infections. Its action is due to the iodide ion. It is assumed that its efficacy in the treatment of various types of cysts is is due to modification of the way in which production of the carcinogenic estrone and hydroxyestrone derivatives is modified towards estriol which is not carcinogenic. Oral use of SSKI in the case of chronic bronchitis and emphysema thins the thick secretions which are difficult to expel. At the same time its antimicrobial activity prevents infections from spreading.