The reprogramming factor KLF4 in normal and malignant blood cells

The Krüppel-like factor 4 (KLF4) is an evolutionarily conserved zinc finger transcription factor that regulates cellular processes in stem cells, epithelial cells, and immune blood cells by controlling gene expression through genetic, epigenetic, and chromatin remodeling. The landmark 2006 publication identified KLF4 as one of the factors involved in reprogramming differentiated cells into pluripotent stem cells, sparking increased interest in KLF4 research a decade after its discovery, particularly in the fields of stem cell research, epithelial cell biology, endothelial cell function, and tumorigenesis. Over the years, KLF4 has emerged as a key transcription factor in modulating innate and adaptive immunity, especially in macrophage differentiation and function. This review summarizes the key findings regarding KLF4 in normal blood cells and leukemia.