I’ve read he and his staff have recieved numerous threats. It could be about that.
There’s more info here...
http://www.kctv5.com/story/19370301/rep-todd-akin-will-hold-news-conference-friday-afternoon
I guess by 4PM they mean Central Time.
Grrr...
His threats are probably from his wife who I've heard is controlling and wears the pants* in his family.
*Hyperbole only!