LEF1 has also been purported to have utility as a prognostic biomarker, since its high expression has been significantly associated with disease progression and poorer prognosis in chronic lymphocytic leukaemia (CLL) [89], acute lymphoblastic leukaemia (ALL) [90,91], small B-cell lymphomas [86], solid pseudopapillary neoplasms and pancreatic neuroendocrine tumours [92], oesophageal squamous cell carcinoma [93], nasopharyngeal carcinoma [94], deep penetrating nevi [62], and with metastasis in colorectal cancer [95]. The gene discussed is LEF1; the disease is B-cell chronic lymphocytic leukemia.