Recently, a Gα q-coupled receptor was discovered that mediates at least some of the many activities of estrogen.  At the time, this discovery generated considerable controversy, as it ran counter to what was then the understanding of how steroid hormone signaling worked.  Which of the following observations might have led the investigators to suspect the existence of this newly discovered receptor?     A. Activities of estrogen apparent less than 1 minute after application of the hormone   B. The growth promoting activity of estrogen   C. The presence of estrogen nuclear receptors in cells not previously known to respond to the hormone   D. Estrogen is found in much higher concentrations in adult women than adult men   E. Uptake of estrogen by target cells

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