p53 expression patterns by immunohistochemistry as a readout for TP53 alterations. (A) p53 immunohistochemistry showing high-level (24%) mutant protein accumulation in a trephine bone marrow biopsy with AML (×20). (B) Violin plot showing median and quartiles, with smoothed width reflecting frequency distribution of p53 accumulation levels in bone marrow samples with TP53 mutant and wild-type AML. p53 accumulation is measured using digital image analysis-assisted immunohistochemistry; percentage values represent cells with strong (3+) staining intensity. Cases with mutant p53 truncating pattern are excluded. Dashed line intersecting x-axis depicts 7.2% cutoff. (C) p53 immunohistochemistry showing loss of signal (truncated) mutant pattern. Signal in background stromal elements presents internal control (×20). (D) ROC curve demonstrating an AUC of 0.965 (95% CI: 0.939-0.991), indicating a robust predictive ability for p53 immunohistochemistry to distinguish between AML with mutant and wild-type TP53. (E) Estimates of mutant p53 clone size by dominant VAF and protein expression among p53^high and (F) p53^truncated. (G) Combined aCGH and SNP analysis of the TP53 gene in AML case with intact TP53 CN; right panel shows corresponding p53^high expression by immunohistochemistry [A, C, G: 20× magnification, hematoxylin counterstain].