YY1 and plasma cell myeloma: YY1 (Yin‐Yang‐1) is a zinc‐finger transcription factor that belongs to the GLI‐Krüppel gene family 8 and abnormally expressed in lots of cancer such as colon cancer 9, non‐small‐cell lung cancer 10, and myeloma 11, indicating that it has key roles in carcinogenesis.