Table 2. Responses of mononuclear cells from healthy donors to 1,25D or ATRA.

Healthy	CYP24A1 expression	POR expression
No	1,25D-induced	1,25D-induced	ATRA-induced
1/2014	2 633 x	downregulation	downregulation
2/2014	6 109 x	downregulation	1.9 x
3/2014	4 713 x	downregulation	downregulation
4/2014	5 075 x	downregulation	downregulation
5/2014	2 163 x	downregulation	1.05 x

Cells from peripheral blood of healthy donors were exposed for 96 h to 10 nM 1,25D or to 1 μM ATRA. Then the mRNA was isolated and the expression of CYP24A1 and POR genes was studied in Real Time PCR.