(Top panel) The effect of added APC on the APTT of plasma from the index patient with factor V Cambridge (Thr³⁰⁶; ▵) compared with patients heterozygous (○) and homozygous (•) for the Gln⁵⁰⁶ mutation and a normal control (Arg⁵⁰⁶; □). (Bottom panel) APC resistance of family members with (I.2 [▵] and II.1 [▴]) and without (I.1 [□] and II.2 [▪]) the Thr³⁰⁶ mutation.