Methods of proteomics were used to show the influence of parathyroid hormone (PTH, fragment 1-34) on osteoblasts as a major component of the hematopoietic stem cell niche. It was found that a number of proteins are changing in response to PTH treatment for 4, 8 and 32 hours. The experimental work-flow has been optimised for the systematic identification of protein level changes upon cellular exposure to different environments.