SLC35B4 and infection: To preliminarily compare the role of BmEcR-B1 and BmEcR-A in response to BmNPV, their relative expression levels in four immune-related tissues of YeA (resistant strain, LC50 > 109 OB/mL) and YeB (susceptible strain, LC50 = 105 OB/mL) after BmNPV infection at 48 h were analyzed using RT-qPCR.