Primary human skeletal muscle cells (Lonza) were treated with LLC1 conditioned medium, LLC1 conditioned medium plus Calcitriol, LLC1 non-conditioned medium or LLC1 non-conditioned medium plus Calcitriol for a period of 24 hours prior to isolation of RNA. Overall design: To assess the effects of molecules produced by LLC1 cells on primary human skeletal muscle cells, LLC1 cells were grown and conditioned medium from LLC1 cells with or without added calcitriol was added to primary human skeletal muscle cells for 24 hours prior to the isolation of RNA.