HC-Pro appears to be a very good servant of its master: most of HC-Pro’s interactions with host proteins (such as the 20S proteasome, methyltransferase, transcription factor eIF4E, salicylic acid-binding protein 3, and microtubule-associated protein HIP2) facilitate the spread of viral infection and modulate the cellular environment, promoting virus accumulation, exacerbating symptom severity (interactions with MinD, Rubisco, and ferredoxin) and suppressing RNA silencing (interactions with host proteins VARICOSE and the calmodulin-like protein). This evidence concerns the gene UBE2K and viral infectious disease.