The M541L mutation has been implicated in hematological malignancies. It may help to identify a subgroup of cases who may benefit from low dose imatinib therapy. KIT mutations are also associated with Gastro Intestinal Stromal Tumors. The KIT variant M541L was originally thought to be associated with increased risk of certain tumors such as aggressive fibromatosis (AF; Dufresne et al., 2010). However, larger scale studies have shown that the prevalence of this mutation within AF does not differ from that of the general population and this variant was not found to be tumor-specific, classifying it as a single nucleotide polymorphism and non-pathogenic (Grabellus et al., 2011).