For GPL Code
1. If the company modifies GPL software, or if a part of GPL software is added to some proprietary code, then the modified work must be made freely available.
2. If the company combines proprietary code with GPL software, and the resulting product is published as a whole work, then the same result follows. What is considered a "whole work" will likely turn on a number of technical issues, such as how closely the programs interact, how they are linked, and how the proprietary program loads with the kernel.
On the other hand, if the company's proprietary code combined with GPL software is identifiable and reasonably considered independent and separate, then it may remain free of the GPL taint when distributed as a separate work. In addition, merely placing a proprietary program on the same storage medium with GPL software does not taint the proprietary code.