Keeping in perspective tumor heterogeneity and single-cell genome sequencing in addition to highlighting co-occurring or mutually exclusive mutations also facilitates the approximation of frequency of individual mutant alleles in cancer with one study relating the cytotoxic response to selective FLT3 inhibition with a high allelic mutant burden in an FLT3/ITD specimen [23-24]. This evidence concerns the gene FLT3 and cancer.