Compared to the non-IL-2 group, patients receiving Ld-IL2 treatment showed reduced bacterial infection (1.4% 3/219 v.s. 6.1%, 27/446, P-value = 0.006), virus (5.9%, 13/219 v.s. 17.9%, 80/446, P-value < 0.001) but no difference was observed to fungal infections which was rare in our cohort, respectively (Table 2). This evidence concerns the gene IL2 and bacterial infectious disease.