CT scan and MRI imaging assessment. Patient no. 1: Comparison of abdominal axial CT scans performed before (January 28, 2012; left) and on day 37 (May 23, 2012; right) of treatment showing regression of the infiltration around both kidneys (white arrows), evidenced by the decreased thickness (right kidney: 24.8 to 18.2 mm, left kidney 22 to 12.4 mm). Patient no. 2: Comparison of MRI performed before (left) and on day 36 (right) of vemurafenib treatment showing regression of ECD orbital infiltration. Comparison of abdominal axial CT scans performed before (March 29, 2012; left) and on day 39 (May 25, 2012; right) of vemurafenib treatment showing regression of the infiltration around abdominal aorta (white arrows): latero-aortic infiltration from 10.8 to 6.5 mm thick, and posterior infiltration from 6.5 to 4.6 mm thick. Patient no. 3: comparison of cardiac MRI, 4-chamber view: (A) February 21, 2012; see the infiltration of the atrial septum, the posterior wall and the free wall of the right atrium (white arrows); (B) July 19, 2012; note the regression of the infiltration.