LICENSE_PhysiCell_Studio.txt

PhysiCell Studio is open source software. Since it currently uses PyQt5, it needs to adhere to the PyQt5 license (rf. https://pypi.org/project/PyQt5/):

"PyQt5 is released under the GPL v3 license and under a commercial license that allows for the development of proprietary applications."

(Note that it is a similar license situation with Qt: https://doc.qt.io/qt-6/licensing.html)