USP3 and neuroblastoma: Interestingly, the PPP1R26-AS1-associated gene PPP1R26 was differentially expressed in all of the conditions [Tumor vs. MNCs, DTCs vs. MNCs, and DTCs (relapsed) vs. MNCs (relapsed)], whereas USP3-AS1-associated coding genes USP3 and FBXL22 were differentially expressed only in primary neuroblastoma tumor.