CES identified a somatic, pathogenic variant of KRAS (c.37G>T, p.Gly13Cys, variant allele frequency 19.6%) from a patient with unknown cause of anemia and thrombocytopenia (Incidental case 1), which made the genetic diagnosis of RAS-associated lymphoproliferative disorder. The gene discussed is KRAS; the disease is lymphoproliferative syndrome.