CD22 and Autoimmunity: Furthermore, the analysis of CD21 (Figure 4M), a marker known to help maintain memory B cells, and CD22 (Figure 4N), known for its role in maintaining immune tolerance and reducing the risk of autoimmunity, both showed a significant decrease in T21 lungs compared to controls (respectively, 0.001 ± 0.0009 vs. 0.02 ± 0.007; n = 6; p = 0.024 and 0.01 ± 0.006 vs. 0.04 ± 0.007; n = 7; p = 013).