We know about formation of (stellar mass) black hole under gravitational collapse in classical theory. But what is the result according to full quantum mechanical treatment? Can anybody tell? I have found one paper according to which, formation of trapping horizon can be questioned in semiclassical treatment (see arXiv:0712.1130). very recently I found another paper where even in classical theory formation of black hole has been questioned under certain conditions (see arXiv:0801.0294). I have not read the details, but I admit this type of issues depress me because if black holes do not exist, some really interesting problems in theoretical physics will go away.