There have been a lot of people, some even here, who would rather think the bloodied print within the apartment was just an invention by the press. I disagree now for there are just too many references to the FSS, the lab that performed the DNA testing.
I think it fits in with the concept of "woke and wandered" and "hurt on the way toward the secondary reception". Imagine the odds of that; Kate walking back to do her check stepping on a drop of Madeleine's blood and the blood forming a print with the toe facing toward the bedroom door! There are only 15 meters or so of shared path in that scenario, but there needs to be some shared path for the blood to get onto the shoes of those who entered the apartment.
It is wrong to think the blood could have originated "anywhere", for the paths of Kate didn't take her everywhere, that night she walked to the Tapas at 8:30 and back at 10:00 when she walked back to the apartment. Plus the two trips for the alarm. So she walked/ran the short section from the gate to the reception 4 times that night and that is about the extent of the places she went (according to her) and no one claims otherwise.
If it wasn't Kate's shoe tread pattern was it Fiona's for she was a small lady too, and may have taken a size 6 shoe. 2 recorded trips for Fiona. Rachael does enter the apartment, and I'd say Jane took a larger shoe altogether.
It is a shame the shoe tread patterns were not available for us to compare.