TLR2/1-induced cathelicidin (hCAP) in monocytes correlates with levels of serum 25OHD in ex vivo culture supplements. Change in levels of monocyte hCAP mRNA following activation of TLR2/1 by 19 kDa lipopeptide (19 kDa, 1 ng/ml) related to the concentration of: A) 25OHD; B) 1,25(OH)2D in 10% human serum used for autologous monocyte cultures. Concentrations of 25OHD [25OHD] and 1,25(OH)2D [1,25(OH)2D] are shown as ng/ml and pg/ml respectively on the lower x-axis, with a corresponding nM and pM reference point shown on the upper x-axis.