RecruitingBehavioural interventionPrecision-MRD: Prospective Observational Study of Biomarker-directed Systemic Therapy for Colorectal Cancer Patients With Minimal Residual DiseaseThe goal of this clinical research study is to learn about the effects of biomarkertargeted therapy on ctDNA in patrticipants with CRC and MRD. This is an observational study. Participants will be monitored while receiving biomarker-directed therapy that is determined by your treating oncologist (cancer doctor) per standard of care, independent of this study.