Fig. 5: Clinical significance of the RPS24 ex4:3 bp isoform in cohorts of patients with breast cancer.

a The distribution of ex4:3 bp isoform proportions across molecular subtypes in TCGA breast cancer data, showing significantly higher expression in luminal subtypes (LumA and LumB) compared with HER2 and basal subtypes. n indicates the number of samples in each group. Molecular subtypes: LumA (luminal A: ER⁺/PR⁺/HER2⁻, low proliferation), LumB (luminal B: ER⁺ with high proliferation or HER2⁺), HER2 (HER2 enriched: ER⁻/PR⁻/HER2⁺), basal (basal-like: triple-negative, ER⁻/PR⁻/HER2⁻). b Correlation between ex4:3 bp expression and developmental lineage scores in TCGA. Ectoderm score shows the strongest positive correlation with ex4:3 bp expression, particularly in ER⁺ samples (r = 0.44) than in the ER⁻ samples (r = 0.32). By contrast, mesoderm and endoderm scores showed weaker or negative correlations, whereas the stemness score showed weak correlations in opposite directions for ER⁺ and ER⁻ samples. c Independent validation using CPTAC breast cancer data. Similar pattern of ex4:3 bp isoform distribution across molecular subtypes as observed in TCGA. d Analysis of MBC project data. Left: higher ex4:3 bp expression in ER⁺ samples than in ER⁻ samples (P = 4 × 10⁻⁵). Right: significantly lower ex4:3 bp expression in ER⁺ samples with distant lymph node metastasis (P = 4 × 10⁻²), suggesting that decreased expression of this isoform correlates with metastatic progression.