<qa>  What is the center of the line from the xiphoid process to the naveThe late prof. Masaharu Katsumi at the Wakayama Medical University found two tender points K1 and K2 for IBS forty seven years ago. The author found another tender point K3. K1 is one quarters of the distance from the center of the navel to the right anterior superior iliac spine. K2 is one quarters of the distance from the center of the navel to the upside of the symphysis pubis. K3 is the center of the line from the xiphoid process to the navel. There are three relevant lines; the K1-K3 line, the K2-K3 line, and the line of identical length to the K1-K3 line originating from K2 and running parallel to the K1-K3 line. The author named these lines N line collectively. 