SEPTIN7 and breast cancer: However, other septins such as SEPT2 and SEPT7 have been shown to colocalize with actin fibers and modulate their formation in nonmalignant cells such as fibroblasts (Calvo et al., 2015), lymphocytes (Gilden et al., 2012) and endothelial cells (Liu et al., 2014), as well as breast cancer cells (Zhang et al., 2016).