XIAP^G466X protein expression. (A) Western blot analysis of XIAP and XIAP^G466X protein expression. Lysates from PHA-expanded T-cell blasts derived from healthy control (Ctr.), male patients (III-2, III-1, and II-5), and a female carrier (II-6, sister of II-5) were immunoblotted with anti-XIAP antibodies and with anti-Ku70 antibodies as loading control. II-6 is a heterozygous carrier expressing both XIAP and XIAP^G466X proteins. (B) Expression of V5-tagged forms of XIAP and XIAP^G466X proteins in 293T cells. Total lysates were prepared 48 hours after transfection and immunoblotted with anti-V5 antibodies.