CCL2 and Pleural effusion: Lansley et al delivered fibrinolytics to the pleural space of mice and proposed that t-PA induces the intrapleural levels of MCP-1 and reported a correlation between the MCP-1 levels and the volume of pleural effusion.22 MCP-1 has been identified as a promoter of vascular permeability and an inflammatory cell recruitment factor in malignant pleural effusion.21 To this end, the authors suggested that these abilities may explain the PF formation.