(A) Blood parameters including absolute lymphocyte count (K/μL), percentage lymphocytes (% lymph), RBC mass (M/μL), hemoglobin (g/dL), and hematocrit (%) were measured in WT/HET (n = 18), KO (n = 6), and AAV-SPL–treated KO (AAV) mice (n = 8). All mice were euthanized at 28 DOL. All parameters were evaluated using unpaired 2-tailed t test with Bonferroni’s correction. Welch’s correction was applied when appropriate. For absolute lymphocyte count, WT/HET vs. KO, P < 0.004; AAV vs. WT/HET, P < 0.0002. For percentage lymphocytes, WT/HET vs. KO, P = 0.006; AAV vs. WT/HET, P <0.0002. For RBC mass, WT/HET vs. KO, P = 0.0018. For hemoglobin, WT/HET vs. KO, P = 0.0048. For hematocrit, WT/HET vs. KO, P = 0.0026. For RBC mass, hemoglobin and hematocrit, AAV vs. WT/HET, there was NSD.