Upon admission, routine laboratory tests were performed, revealing a complete blood count without leukocytosis, neutrophilia, or lymphopenia; grade I anemia according to WHO criteria; preserved renal function; normal liver function tests; elevated lactate dehydrogenase (LDH); elevated C-reactive protein (CRP) and ESR; negative viral panel for hepatitis and HIV; and negative serology for syphilis. The gene discussed is CRP; the disease is hepatitis A virus infection.