SERPINE1 and cancer: The anti-invasive effect was determined by a modified Boyden chamber assay using 1 μM CBD and 72 h incubation period, whereas the PAI-1 expression (a key factor for tumor invasion and metastasis; a high concentration of PAI-1 is considered a poor prognostic factor in many types of cancer, such as lung, colorectal, gastric, and breast) was determined by RT-PCRusing 1 μM CBD over a 48 h incubation period [88,89].