ARID2 and cancer: We used a pCAS2.1 splicing reporter mini-gene functional assay that was adapted from previous publications (Bonnet et al., 2008; Gaildrat et al., 2010; Malone et al., 2016; Tournier et al., 2008; Vreeswijk and van der Klift, 2012), to validate SCMs in 11 cancer genes, including two originally annotated silent mutations in PARP1, RAD51C, two splice site mutations in TP53 and BRCA1, and several missense mutations in ARID2, BAP1, BCOR, CDH1, KMT2A, PTEN, and TSC2. Wild-type and mutant exons were cloned into a pCAS2.1 vector (Gaildrat et al., 2010) and transiently transfected into HEK293T cells.