ESR1 and breast cancer: Considering that the CDYL protein derived from the transcript CDYL‐203 can associate with EZH2, while the putative protein derived from CDYL‐204 lacks the domain involved in the interaction with EZH2, this raises the intriguing possibility of an RNA‐guided assembly of transcriptional regulatory complexes that can fine‐tune gene expression programs in a context‐specific manner, particularly in ERα+ BC.