To further investigate the relationship between IL-1α and IL-1β expression and periapical granuloma progression, the periapical granuloma group was divided into three different inflammation grade subgroups, including 16 samples in the mild inflammatory cell infiltration subgroup, 32 samples in the moderate inflammatory cell infiltration subgroup, and 37 samples in the severe inflammatory cell infiltration subgroup. This evidence concerns the gene IL1A and periapical granuloma.