LRRC15 and cancer: SLC3A2 can associate with ITGB4 in LC to regulate integrin signaling, cell survival, and cell migration, and in turn, ITGB4 might be related to leucine-rich repeat-containing protein 15 (LRRC15), which may promote cancer metastasis by affecting cell–cell and cell–matrix interactions (Figure 6), and by activating the β1-integrin/FAK signaling pathway [43].