CD4 and neoplasm: However, tumor free SH2D2A-deficient mice displayed a significantly higher number of GB113 positive SP CD4+ thymocytes compared to tumor free wild-type mice (Figure 7B), indicating less extensive deletion of GB113 positive SP CD4+ thymocytes in the absence of SH2D2A. In the tumor-draining lymph node, SH2D2A did not affect the number of GB113+ CD4+ T cells (Figure 7C).