HLA-G and oral lichen planus: According to the data in Table 1, Kruskal–Wallis test suggested a significant difference among these three group Post-hoc Tukey test-pairwise comparison- suggested that β2-microglobulin in healthy group was significantly less than that in Oral lichen planus and Oral Squamous Cell Carcinoma groups (P = 0.042); while it was the same in both groups of patients (P = 0.997) (Table 2).