TNF and rheumatoid arthritis: In RA patients, the population of TNFα-producing Vδ1 cells decreased from the second to the third trimester and increased from the third trimester to the postpartum time point (second to third trimester analyzed by percentage of positive cells and by MFI: P = 0.04; third trimester to postpartum analyzed by MFI: P = 0.04; Additional file 1: Figure S1).