IL12B and infection: Moreover, in a related project, micro-array analysis of Mφ1 infected with live Salmonella for 1, 2, 4, 8 and 24 hours revealed that infection did not induce IL12A (IL-12p35) transcription, whereas IL12B (IL-12p40) and IL23A (IL-23p19) transcription were both upregulated in response to Salmonella (van de Wetering, unpublished data).