## 5 Conclusions  
In both tested cell lines, we obtained results indicating that cyprodinil may be potentially dangerous both to humans and, consequently, to the environment. The obtained effects of its action are similar in both cell lines. In the A-375 cell line, concentrations of 0.05 uM and 0.2 uM proved to be the most stimulating for cancer cell growth, while in the DLD-1 cell line, these concentrations were 0.025 uM and 0.2 uM. Furthermore, it was shown that increased glutathione levels were observed at the above-mentioned concentrations, while the lower concentrations tested activated the expression of genes responsible for the synthesis of antioxidant enzymes more strongly. This, in turn, may be related to the easier penetration of cyprodinil into cells at the lower concentrations tested. In our opinion, the results indicating that this pesticide penetrates more readily at lower concentrations seem concerning. These data can provide important information for the EFSA to determine the maximum permitted level of cyprodinil in food. The tested fungicide belongs to a group of significant environmental micropollutants. It poses a threat to humans, animals, and other environmental components. The presented research results can be described as preliminary, conducted only on two selected tumor lines, which does not provide a complete picture of the existing problem. This is undoubtedly a limitation of our research. In the future, these studies should be expanded to include other tumor lines, including healthy lines, and a panel of in vivo studies should be conducted. We emphasize that in vitro studies do not reflect the interactions between different cell types occurring in tissues. Therefore, their expansion is crucial, which we believe is another important step in this direction. In our work, we examined, among other things, gene expression for selected enzymes associated with oxidative stress. Further research should focus on understanding the signaling pathways responsible for transmitting signals generated by cyprodinil entering both cancer and healthy cells. It also seems crucial to use transcriptomics methods to detect specific genes responsible for the synthesis of proteins involved in the pesticide response. This will confirm that the fungicide under study is indeed a carcinogen, which may lead to the future phasing out of such active substances in agriculture.  
Conceptualization, A.J.-T.; methodology, A.J.-T., U.W., E.W., R.K., M.N. and P.K.; software, A.J.-T., U.W., E.W., R.K., M.N., B.L., P.K. and J.K.; validation, U.W., E.W., B.L. and A.C.; formal analysis, [PERSON]-T., R.K., A.C. and J.K.; investigation, [PERSON]-T., N.W., G.S., U.W., R.K., M.N., B.L., P.K. and J.K.; resources, [PERSON]-T., E.W. and A.C.; data curation, [PERSON]-T., N.W., G.S., U.W., E.W., R.K., M.N., P.K. and A.C.; writing--original draft preparation, [PERSON]-T., N.W., G.S., M.N., [PERSON] and B.L.; writing--review and editing, A.J.-T., U.W., E.W., M.N., M.C.-P. and P.K.; visualization, U.W., E.W., R.K., M.N. and A.C.; supervision, A.J.-T.; project administration, A.J.-T.; funding acquisition, A.J.-T., U.W. and E.W. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Ministry of Education and Science, Poland, under the research project number WZ/WB-IIS/7/2025.  
Not applicable.  
Data Availability Statement: The data presented in this study are available on a reasonable request from the corresponding author.