Enables pre-mRNA intronic binding activity and single-stranded RNA binding activity. Involved in several processes, including intergenic mRNA trans splicing; primary sex determination; and regulation of gene expression. Located in nucleus. Expressed in body wall musculature; intestine; pharynx; and vulval muscle. Human ortholog(s) of this gene implicated in dilated cardiomyopathy; hypoplastic left heart syndrome; myotonic dystrophy type 1; and type 2 diabetes mellitus. Is an ortholog of human RBFOX1 (RNA binding
fox-1 homolog 1) and RBFOX3 (RNA binding
fox-1 homolog 3).