TP53 and systemic lupus erythematosus: Furthermore, SLE-AH had higher p53 levels (Additional file 1: Fig. S5a) and apoptotic cell ratios (Additional file 1: Fig. S5b) than those from LN, Nil or HC (For p53, p = 0.038 for LN, p = 0.004 for Nil, p < 0.001 for HC; for apoptotic cell, p = 0.036 for LN, Nil or HC).