Table 1.

Rheumatoid arthritis related biomarkers of programmed cell death.

Name	Potential role	Ref.
MCL-1	It is associated with the degree of inflammation and TNF-α level in addition to inhibiting the apoptosis of FLS.	(21)
PDCD5	It is negatively correlated with CRP, ESR, IL-17, and TNF-α levels.	(49, 50)
β2-R	It is negatively correlated with disease severity.	(89)
Cell-free nucleosomes	It is associated with disease severity.	(156, 157)
Myeloperoxidase	It is associated with disease severity.	(156, 157)
Neutrophil elastase	It is associated with disease severity.	(156, 157)
MPO-DNA complex	It is associated with ACPA and RF levels.	(158)
Calprotectin	It is associated with the serum markers of inflammation, CRP, ESR, and baseline levels of anti-CCP, as well as predicting the progression of joint destruction and drug efficacy.	(162, 163)
14-3-3η	It is closely associated with disease severity and anti-cyclic citrullinated peptide antibody levels.	(172)
IL-18	It is associated with inflammation.	(183)
SNP of NLRP3	It is related to RA susceptibility and response to anti-TNF-α therapy.	(188)