Hence, we used D-Val-Leu-Lys-AMC as an established plasmin substrate (Gyzander and Teger-Nilsson 1980; Kato et al. 1980; Li et al. 2018; Wu et al. 2019; Zeitlmayr et al. 2022) and compared plasmin activity of A549 adenocarcinoma cells derived from a primary lung tumor with metastatic H1299 large cell lung carcinoma cells. This evidence concerns the gene PLG and adenocarcinoma.