IL6 and cancer: Further, the researchers were able to show that the increased expression of cytokines (IL-8, MCP-1, IL-6, and TNF-α) by the cancer cells led to endothelial adhesion junction degradation, increased gap formation and loss of endothelial barrier function that was accompanied by the activation of the Src/ERK/FAK signaling pathway and downregulation of the vascular barrier regulators VE-cadherin and VE-PTP (Saha et al., 2020).