show the role of Cajal bodies in cancer progression, where small Cajal body-specific RNAs 15 (SCARNA15) regulate the alternative splicing by modulating the pseudouridylation of U2 spliceosomal RNA, which influences the suppressor tumor genes like p53 and ATRX. Suppression of SCARNA15 downregulates the p53 expression, followed by cancer cells proliferation (72). This evidence concerns the gene ATRX and cancer.