You should definitely not ignore it. Pain is there for a reason.
Where did you get your running shoes (I'm assuming that they are proper running shoes) and were they fitted by someone who knows their stuff?
Knees take a lot of abuse when running and the common themes for people who end up suffering from knee pain is not enough stretching of the rest of the leg and little or not core strength work. Including both of these in your training programme will far lessen your risk of injury.
Stretching should be done on a daily basis. 20 minutes of stetching before bed should suffice and should focus on quads, hamstrings and calves.
Core strength work should be done 2 or 3 times a week and should focus on abs, back, glutes, quads and hamstrings. Any muscle imbalances in any of these areas can lead to problems on other joints (particularly knee).
I'm not sure what the specific cause of your knee pain may be because I have only ever suffered from ITB problems around the knee (which normally affects the outside edge of the knee, not where you describe the problem to be) but it could be that you are locking your knees out when running or trying to put your foot too far in front when you land and therefore putting a lot of strain on your knee as your leg acts as a brake. Try to focus on landing your foot underneath your body when you run, this will make you feel initially like you are leaning forward but it might help.
