Patellofemoral pain can be from different sources. Dr. Powers has described the 2 causes of Patellofemoral pain as to be the train moving abnormally on the track (getting pulled outwardly from a tight ITB) or the track moving abnormally under the train (the femur moving into a knock kneed position causing the patella to track outwardly).
Either way, we usually see a weakness of the gluteus medius, which causes the pelvis to drop in the weight bearing phase of walking. It can lead to an overuse of the muscle attached to the ITB.
Treatment should include foam rolling the ITB, and strengthening the gluts. It should also include an examination of the mobility and mechanics of the foot (many people pronate, which causes the knee to move inward).
If glut strength is an issue, my favorite exercises are clams, crab walking, and hip hikes.