COL18A1 and acute lymphoblastic leukemia: The activity of COL18A1 rs2274808 was further validated by a study which determined that a defect in COL18A1 would change endostatin synthesis in a Salvadorian population (Mahajan et al., 2010), consequently leading to an antiangiogenic disorder, such as Knoblock syndrome and ALL; however, some authors have indicated that children with ALL have variable levels of endostatin (Dagdas et al., 2011), which makes it difficult to accurately explain its relationship with the disease (Schneider et al., 2007).