(A) Box plots showing CCNA2 mRNA expression levels (log₂ over NC) in pCRC (n = 2239) and mCRC (n = 67) tumors. Expression was normalized to normal tissue samples. CCNA2^hi levels were defined as expression above 1 (horizontal red line), and CCNA2^non-hi levels were defined as expression below 1. For each box plot, the median and ranges are indicated. CCNA2 expression was compared between group using a multiple-comparison ANOVA. (B) CCNA2 mRNA expression levels in stage 1–2 (n = 834) and 3–4 (n = 785) primary CRC tumors. Expression was normalized to normal tissue samples as in A. CCNA2 expression was compared between groups using a 2-tailed Student’s t test; data are expressed as the mean ± SD. (C) Cyclin A2 protein expression was determined by immunostaining using the anti–cyclinA2 antibody from Abcam validated on cyclin A2–deficient colon tissue and expressed as the number of positive cells per mm² of tumor, analyzed from a TMA of CRC tumor samples derived from patients with stage 1 (n = 23), stage 2 (n = 48, with 24 MSS tumors and 24 MSI tumors), stage 3 (n = 30), and stage 4 (n = 26) CRC. Data represent the mean ± SEM. *P < 0.05 and **P < 0.01, by unpaired, 2-tailed Student’s t test. (D) Kaplan-Meier RFS of patients defined as carriers of CCNA2^hi (n = 988) or CCNA2^non-hi (n = 894) tumors. Survival rates were calculated using the Kaplan-Meier method and compared with the log-rank test. (E) Analysis of CCNA2 mRNA levels in the different consensus CRC subtypes: CMS1 (n = 389), CMS2 (n = 640), CMS3 (n = 343), and CMS4 (n = 604) expressed as log₂ over NC as described in A (multiple-comparison ANOVA). (F) Kaplan-Meier RFS curves for all patients with pCRC according to both the CCNA2-based classification (CCNA2^hi and CCNA2^non-hi classes with the solid curves and dashed curves, respectively) and CMS subtypes.