ESR1 and inflammatory breast carcinoma: In the 19 IBC patients included in this study, pathogenic or likely pathogenic variants were most frequently detected in TP53 (9/19 patients; 47.3%), PMS2 (5/19; 26.3%), MRE11 (5/19; 26.3%), BRCA1 (2/19; 10.5%), RB1 (2/19; 10.5%), AR (2/19; 10.5%), and PTEN (2/19; 10.5%) in malignant tissue/cells and/or cfDNA samples; others were detected in BRCA2, PALB2, PMS1, MUTYH, KMT2C, MEN1, MSH2, CHEK2, NCOR1, PIK3CA, ESR1 and MAP2K4 (Figure 1A).