The disease monitoring includes measuring disease activity by using composite indices for disease activity (Ankylosing Spondylitis Disease Activity Score [ASDAS] or Bath Ankylosing Spondylitis Disease Activity Index [BASDAI]) and laboratory tests (C-reactive protein [CRP]) and imaging, and patient-reported outcomes (PRO) capturing patient perspectives [6, 7]. The gene discussed is CRP; the disease is ankylosing spondylitis.