MAPK1 and infection: Other members of the MAPK family that we tested did not appear to be involved in establishing HAstV1 infection because neither 50 μM SB 203580, which blocks p38 activation (Figure 1A, E and e), nor 50 μM JNK inhibitor II, which selectively inhibits JNK (Figure 1A, F and f), had a significant effect on viral capsid gene expression.