MYC and carcinoma: Since tylophorine was reported to block c-Myc protein expression by arresting the RNP complex containing caprin-1 protein and c-Myc mRNA in c-Myc highly expressed carcinoma cells18, we further examined whether tylophorine also blocked IκBα protein expression, which was induced upon TGEV infection (Fig. 2A-a), through a similar mechanism.