The dense tangle of transmitters, transcription factors, transcripts and translations of the information encoded by the scores of genes activated by signals from PTH-activated PTHR1 receptors. The stream of signals from the receptors includes a burst of cyclic AMP-dependent protein kinase (PKA) which is needed to start the bone-building machinery. But the signal mix and the cascades it triggers depend on to what other receptors the PTHR1s are linked and to what signalers-loaded scaffolds, such as NHERFs -1 and -2, the PTHR1s are attached. The upshot of this is a seemingly ever-growing intricate web of responses hidden among which are the actual bone-building drivers. The challenge is to separate the driving "wheat" from irrelevant "chaff ".