Austin Carlile, front man of Of Mice and Men has left the group due to an ongoing battle with Marfan Syndrome, a genetic disorder that affects the body’s connective tissue. You can read a statement from Carlile below which he posted on Twitter. Carlile formed Of Mice and Men in 2009 after leaving his band Attack! Attack! The band released their album Cold War in September.
https://twitter.com/austincarlile/status/814968429090316288