BGI, the world’s largest genomics organization, has developed a new single-cell genome sequencing technology. In two papers, published today in the same issue of Cell, BGI researchers applied their new single-cell sequencing (SCS) method to identify the genetic characteristics of essential thrombocythemia (when the body produces too many blood platelets) and clear cell renal cell carcinoma (a kidney cancer). They demonstrated that single cell analyses of highly heterogeneous tissues provide much clearer intratumoral genetic pictures and developmental history than previous bulk tissue sequencing. The availability of this method opens new ways for the genetic study of tumors at single nucleotide resolution, especially for those where it is difficult to identify key mutations by previous bulk tissue sequencing.