S100A8 and cancer: In cancer cells, S100A8/A9 is the main modulator of apoptosis (Qin et al., 2010), migration, invasion (Yin et al., 2013), brain metastasis (Monteiro et al., 2022), drug resistance (Zavorka Thomas et al., 2021) and many other processes, acting as a dual and diverse sensor in different steps of tumor progression, some of which are described below.