Laboratory study should consist of a complete blood count (CBC), metabolic assessments (electrolytes, blood urea nitrogen (BUN), creatinine (Cr), and fasting blood glucose), ESR, c-reactive protein (CRP), in addition to antinuclear antibody (ANA), rheumatoid factor (RF), antineutrophil cytoplasmic antibodies (ANCA), hepatitis B and C, and cryoglobulins [30]. The gene discussed is CRP; the disease is hepatitis A virus infection.