Introns derived from the Tulp4 gene can be cyclized to form circTulp4, which can interact with U1 snRNP and RNA polymerase II to regulate the transcription of its parental gene, Tulp4, thus participate in the development of Alzheimer’s disease (AD) (Ma N. et al., 2021). This evidence concerns the gene TULP4 and early-onset autosomal dominant Alzheimer disease.