JAK2 and cancer: Out of these, four genes affected by a somatic SNV in the MSI tumor [AFF3, DROSHA, JAK2, PIK3CA (associated with GC)] and one gene affected by a somatic SNV in the MSS tumor (GATA3) were also listed in the cancer gene census list of the COSMIC database and not mentioned in ExAc or ESP (exome sequencing database, see methods).