TP53 and neoplasm: Therefore, when a TP53 variant is detected in a small fraction of NGS reads from blood, it is critical, before concluding that the presence represents a mosaic TP53 alteration, to respect the following rules: (i) consider the clinical presentation (suggestive or not of the presence of a disease-causing TP53 variant) and medical history (treatments, metastases, etc...) and (ii) confirm the presence of the variant in the tissue from which the tumour originated.