Tim has written a piece speculating on the identity of the third occupant of the side chamber in KV35, a young boy who seems to have got lost in the telling of the DNA tale. In this detailed post Tim examines the possibility of identifying the boy.
In the recent two year study of eighteenth dynasty royal mummies it seems that this boy from a side chamber in valley of kings tomb KV 35 was not included.
There are artifacts from the tomb Kv 35 which belong to a son of Amenhotep II named Webensenu as a result of the mummies found in the tomb there are four candidates to be that prince including this boy or another mummy found attached to a funerary boat belonging to Amenhotep II or either of two skeletons.
Some have speculated that the mummy on the boat was the founder of the twentieth dynasty Sethnakht because of a reused coffin once manufactured for that king was present in the tomb at the time of discovery. Unfortunately the mummy was destroyed more than a hundred years ago when the boat was stolen.