Inclusion Criteria:  Males or nonpregnant, nonlactating females aged 16 to 80 years inclusive. Diagnosis of CD prior to screening using standard endoscopic, histologic, or radiologic criteria. Subjects with patchy colonic inflammation initially diagnosed as indeterminate colitis would meet inclusion criteria, if the investigator feels that the findings are consistent with CD.  Moderately to severely active CD, defined by a total Crohn's Disease Activity Index (CDAI) score between 220 and 450 points, and at least 1 of the following:  Elevated CRP > upper limit of normal ) Elevated fecal calprotectin (FC) (> 250 μg/g) SES-CD > 6, or SES-CD > 3 for isolated ileal disease Physician intends to prescribe IFX as part of the usual care of the subject. No previous use of IFX. Able to participate fully in all aspects of this clinical trial. Written informed consent must be obtained and documented.  Exclusion Criteria:  Subjects with any of the following CD-related complications:  Abdominal or pelvic abscess, including perianal Presence of stoma or ostomy Isolated perianal disease Obstructive disease, such as obstructive stricture Short gut syndrome Toxic megacolon or any other complications that might require surgery, or any other manifestation that precludes or confounds the assessment of disease activity (CDAI or SES-CD) Total colectomy. History or current diagnosis of ulcerative colitis, indeterminate colitis, microscopic colitis, ischemic colitis, colonic mucosal dysplasia, or untreated bile acid malabsorption. Current bacterial or parasitic pathogenic enteric infection, according to SOC assessments, including: Clostridioides difficile; tuberculosis; known infection with hepatitis B or C virus; known infection with HIV; sepsis; abscesses. History of the following: opportunistic infection within 6 months prior to screening; any infection requiring antimicrobial therapy within 2 weeks prior to screening; more than 1 episode of herpes zoster or any episode of disseminated zoster; any other infection requiring hospitalization or intravenous antimicrobial therapy within 4 weeks prior to screening. Has any malignancy or lymphoproliferative disorder other than nonmelanoma cutaneous malignancies or cervical carcinoma in situ that has been treated with no evidence of recurrence within the last 5 years. Known primary or secondary immunodeficiency. PNR to adalimumab, defined as no objective evidence of clinical benefit after 14 weeks of therapy. Subjects with failure to a prior biologic, defined as PNR or SLR, will be excluded when a maximum of 40% of the planned enrollment (approximately 78 subjects) have failure to prior biologic exposure. Concomitant use of oral corticosteroid therapy exceeding prednisone 40 mg/day, budesonide 9 mg/day, or equivalent. Presence of any medical condition or use of any medication that is a contraindication for IFX use, as outlined on the product label. A concurrent clinically significant, serious, unstable, or uncontrolled underlying cardiovascular, pulmonary, hepatic, renal, GI, genitourinary, hematological, coagulation, immunological, endocrine/metabolic, or other medical disorder that, in the opinion of the investigator, might confound the study results, pose additional risk to the subject, or interfere with the subject's ability to participate fully in the study. Pregnant or lactating women, to be excluded based on the physician's usual practice for determining pregnancy or lactation status. Known intolerance or hypersensitivity to IFX or other murine proteins.