Krüppel-like factor 4 (KLF4) was downregulated in breast cancer tissues.
KLF4 was upregulated in TNF-α–stimulated SK-BR-3 breast cancer cells.
KLF4 inhibited proliferation and promoted apoptosis in breast cancer cells.
Overexpression of KLF4 suppressed SK-BR-3 cell tumorigenicity in vivo.