PECAM1 and anemia (phenotype): Repeated immunophenotyping up to 12 months of age demonstrated persistent anemia and severely low numbers of T cells, decreased percentages of recent thymic emigrant (RTE; CD4+CD45RA+CD31+) and naïve CD4+ and CD8+ (CD45RA+) T cells with increased percentages of memory CD4+CD45RO+ and effector memory CD8+CD45RA-CCR7- T cells (Table 1).