SPP1 and cancer: Thus, interaction of osteopontin with cell surface receptors, integrins, and/or CD44 activates JNK, Ras/Raf/MEK/ERK, PI3K/AKT, JAK/STAT, NF-κB, and TIAM1/Rac1 signaling pathways, leading to enhancement of various malignant properties of cancer cells [34].