The IgM KO cells, on the other hand, more rapidly declined to <60% (days 2–4: 52.1 ± 14.9; 55.5 ± 6.7; 56.3 ± 6.5) within 2 days (Figure 1A), indicative of the stronger BCR signaling dependence of lymphoma cells. This evidence concerns the gene BCR and lymphoma.