Cohort A  Inclusion Criteria:  Subjects must be 20 years of age or older. Subjects was diagnosed with anatomic stage II, T3, MMR-P colorectal cancer Subjects had recurrence date information within 5 years follow-up after initial tumor resection surgery Subject is able and willing to provide FFPE sample per protocol Subject is able to comprehend and willing to sign and date the written informed consent document(s) and any applicable medical record release documents for the study  Exclusion Criteria:  No tumor block available from initial diagnosis before any chemotherapy treatment Presence of synchronous tumors No tumor or very little tumor (<5% tumor present) in block as assessed designated pathologist. Tumor types other than adenocarcinoma NOS (not otherwise specified) and mucinous carcinoma as assessed by examination of the H&E slide by designated pathologist. Insufficient RNA (<5 ng/μL or 300 ng) for RT-PCR analysis. Failure of assay to meet pre-specified quality control (QC) specifications.  Cohort B  Inclusion Criteria:  Subjects must be 20 years of age or older. Subjects was diagnosed with anatomic stage II, T3, MMR-P colorectal cancer Subjects had 5 years follow-up information after initial tumor resection surgery Subject is able and willing to provide FFPE sample per protocol Subject is able to comprehend and willing to sign and date the written informed consent document(s) and any applicable medical record release documents for the study  Exclusion Criteria:  No tumor block available from initial diagnosis before any chemotherapy treatment Presence of synchronous tumors No tumor or very little tumor (<5% tumor present) in block as assessed designated pathologist. Tumor types other than adenocarcinoma NOS (not otherwise specified) and mucinous carcinoma as assessed by examination of the H&E slide by designated pathologist. Insufficient RNA (<5 ng/μL or 300 ng) for RT-PCR analysis. Failure of assay to meet pre-specified quality control (QC) specifications.  Cohort C  Inclusion Criteria:  Subjects must be 20 years of age or older. Subjects was diagnosed with anatomic stage III A/B colorectal cancer Subjects had recurrence date information within 5 years follow-up after initial tumor resection surgery Subject is able and willing to provide FFPE sample per protocol Subject is able to comprehend and willing to sign and date the written informed consent document(s) and any applicable medical record release documents for the study  Exclusion Criteria:  No tumor block available from initial diagnosis before any chemotherapy treatment Presence of synchronous tumors No tumor or very little tumor (<5% tumor present) in block as assessed designated pathologist. Tumor types other than adenocarcinoma NOS (not otherwise specified) and mucinous carcinoma as assessed by examination of the H&E slide by designated pathologist. Insufficient RNA (<5 ng/μL or 300 ng) for RT-PCR analysis. Failure of assay to meet pre-specified quality control (QC) specifications.  Cohort D  Inclusion Criteria:  Subjects must be 20 years of age or older. Subjects was diagnosed with anatomic stage III A/B colorectal cancer Subjects had 5 years follow-up information after initial tumor resection surgery Subject is able and willing to provide FFPE sample per protocol Subject is able to comprehend and willing to sign and date the written informed consent document(s) and any applicable medical record release documents for the study  Exclusion Criteria:  No tumor block available from initial diagnosis before any chemotherapy treatment Presence of synchronous tumors No tumor or very little tumor (<5% tumor present) in block as assessed designated pathologist. Tumor types other than adenocarcinoma NOS (not otherwise specified) and mucinous carcinoma as assessed by examination of the H&E slide by designated pathologist. Insufficient RNA (<5 ng/μL or 300 ng) for RT-PCR analysis. Failure of assay to meet pre-specified quality control (QC) specifications.