PCAT18 and acute lymphoblastic leukemia: We selected 12 lncRNAs that have never been associated with childhood ALL previously for further validations, 6 from the group of specific lncRNAs for B-ALL (cluster 1: LINC00958, LINC00114, AL713998.1, AC008060.1, AL590226.1, AC002464.1) and 6 from the group of specific lncRNAs for T-ALL (cluster 2: AC002454.1, PCAT18, HHIP-AS1, AC116351.1, AC247036.1, LINC01222).