JAK2 and cancer: PRMT5 is overexpressed in a large number of cancer types and promotes cell proliferation, migration, and survival.[16] Besides controlling specific gene expression through methylation of histones, PRMT5 also targets certain transcription factors involving in cell signaling.[16] Although PRMT5 was discovered as a JAK2‐binding protein, the role of PRMT5 in the JAK/STAT3 signaling pathway still remains unknown.