KRAS and Increased total leukocyte count: RALD is characterized by persistent monocytosis; often associated with leukocytosis, lymphoproliferation, and autoimmune phenomena, early onset (mostly at the age <5 years old), and resistance to IL2 depletion-dependent apoptosis; and caused by somatic mutations in RAS genes (NRAS and KRAS), which plays an important role in intracellular signaling and control proliferation and apoptosis (204, 206, 207).