philtrum

The philtrum is the midline groove in the upper lip that runs from the top of the lip to the nose.

Folklore:
According to the Jewish Talmud (Niddah 30b), God sends an angel to each womb and teaches a baby all the wisdom that can be obtained. Just before the unborn baby comes out, the angel touches it between the upper lip and the nose and all that it has taught the baby is forgotten.

Medical treatment:
Renzhong is an acupoint below the nose above the midpoint of the philtrum in traditional Chinese acupuncture.