SH2D1A mRNA expression in T cell lines derived from patients with XLP. RNA was extracted from the transformed T cell lines derived from the patients with XLP and a healthy control. Then RT-PCR was performed with primer pairs flanking the coding region of the SH2D1A gene. Marker indicates molecular marker; Jurkat, T-lymphoid cell line, positive control; BJAB, B-lymphoid cell line, negative control; normal, healthy control; P1, patient 1; P2, patient 2; P4, patient 4; blank, amplified without DNA.