1. An information processing apparatus comprising: a three-dimensional region acquisition unit configured to acquire first positional information on a three-dimensional region of an object; a tomographic image acquisition unit configured to acquire second positional information on a tomographic image of the object; and a display control unit configured to cause a display unit to display, with the tomographic image, information on a cross-section of the three-dimensional region, the information on the cross-section representing an intersection of the three-dimensional region and a plane of the tomographic image, wherein the display control unit is configured to determine a display style of the information on the cross-section on the basis of information on a positional relation, obtained by using the first and second positional information, between the cross-section and the three-dimensional region, and wherein the display control unit is configured to cause the display unit to display, with the tomographic image, the information on the cross-section in the display style.