Relevant studies have shown that kynurenine is the primary predictor of N-ace tyrosine (NAC) effect in SLE, The pentose phase pathway (PPP)-connected and NAC-responsive accumulation of kynurenine and its stimulation of mTOR are identified as novel metabolic checkpoints in lupus pathogenesis (Perl et al., 2015). This evidence concerns the gene MTOR and systemic lupus erythematosus.