Final answer:
WPC-50 usually stands for Whey Protein Concentrate with 50% protein content, but this term is not directly referenced in the provided research information.
Step-by-step explanation:
The term WPC-50 is not explicitly mentioned in the provided reference information, which covers the validation of protein hits in pathogenesis-related protein research with statistical significance. However, generally in the context of protein manufacturing, WPC-50 often refers to Whey Protein Concentrate that is 50% protein by weight. Factors like the number of query-matched peptides (cutoff value: <3), the ratio of protein levels in transgenic to wild-type wheat, and calculations involving standard deviation were highlighted in the reference, but these are separate from the definition of WPC-50.