PADI4 and systemic lupus erythematosus: Furthermore, in the SLE-AH lungs, there were higher TUNEL-positive apoptotic cell numbers and up-regulated levels of p53/Bax, increased NETs formation with colocalized CitH3/DNAs and elevated PAD4 levels, and the presence of autophagy with cytoplasmic LC3-positive cells and up-regulated LC3/Beclin-1 expression.