As miRNAs can also regulate genes involved in drug transport, metabolism, and targets, SNPs in miRNA biogenesis proteins are not only related to a predisposition for pediatric ALL but may also participate in drug response or resistance, such as rs639174 in DROSHA, an intronic SNP that has been associated with toxicity during chemotherapeutic treatment [100,101]. This evidence concerns the gene DROSHA and acute lymphoblastic leukemia.