Tridimensional models of CIC15 and its germ line counterpart (GL). Only the amino acids of the VK CDR1 loop containing the 3 mutations (serine → asparagine) are shown here. Balls and sticks represent the unmutated amino acids, whereas the “space-filling” representation (van der Waals surface) highlights the mutations. Atoms: black, N; dark gray, O; and light gray, C.