PGRMC1 is known to be Sumoylated or ubiquitinylated and then degraded by the proteasome pathway, which lead to higher molecular weight species (PMID: 31067491).
2) Additionally, the methods do not say that all results were repeated at least once, and that a representative results figure is presented. Therefore, the reviewer assumes that experiments have only been performed once. The entire set of experiments needs to be replicated to demonstrate reproducibility before it can be considered to publish these results.