We profiled four different mutations in a clonal T cell leukemia diploid cell line (JURKAT) carrying heterozygous mutations in NOTCH1, RUNX1, TP53, and PTEN. When we used SMART-seq+, detection of all of the four mutations within the same single cell was not achieved in any of the cells analyzed. This evidence concerns the gene RUNX1 and T-cell leukemia.