In addition, M1 polarization of primary human macrophages induces proximal PAS usage, leading to the production of mRNAs with short 3’UTRs in physiologically relevant genes, such as IL17RA and TP53RK. IPA events are increased in M1 polarized macrophages affecting genes such as MAP3K8 and WDR33. Both 3’UTR-APA shortening and IPA are further upregulated after CRC co-culture, in particular for MAP3K8 and WDR33. SRSF12 expression is strongly upregulated in primary human macrophages upon M1 polarization. The gene discussed is WDR33; the disease is colorectal carcinoma.