In summary, our first pan-cancer analysis of ABCA1 revealed a statistical correlation between ABCA1 expression and clinical prognosis, genetic variation, immune cell infiltration in different types of tumours and that ABCA1 is aberrantly expressed in various cancers, which further demonstrates the important role of ABCA1 in tumorigenesis and tumour immunity in a variety of cancers. This evidence concerns the gene ABCA1 and cancer.