You need to control your experiments so thatthey can be validated by others

A positive control confirms that your target antigen is expressed on the relevant cells and tissues. A negative control consists of tissues or cells where your target protein is known to be absent. You should always use several positive and negative controls at the same time. If possible, you should confirm the expression of the required target molecule in your sample using more than one assay

Depending on the cells/tissue and IP system/conditions you are using a large number of proteins can be pulled down non-specifically through interactions with the beads, linker, and non-variable regions of the antibody you have used. We recently did both an IP  followed by LC-MS/MS and saw over a hundred proteins identified in the negative control conditions (pre-immune serum). And this does not include proteins that were present but not detected.

Thanks for your nice guidance

Anti-GFP antibodies routinely recommended for IP, since it is a very high binding affinity and therefore we can consider that as a fast, reliable and sensitive control.