Interferon, a cancer treatment, has helped reduce tumors in several patients.
has been learned, particularly in recent years, as to the properties, including modifiability, of this endogenous rhythmicity.
The fundamental problem, however, that of the timing mechanism of the rhythmic periods, has largely eluded any eminently reasonable
1. Recently, scientists have learned a great deal about the biological clock. They know how to change
the rhythm of the cycle, but they have not been able to adequately explain what drives the timing of these periods (Brown).
Or: Recently, scientists have learned a lot about the way organic systems work on a schedule, otherwise known as the
"biological clock," even about how to change its rhythm. However, something they have still not been able to understand or
explain is the timing of the periods (Brown).
2. Lately, scientists have been able to make changes to the biological
clock, which is the pattern that all life follows through growing, living and dying. However, these scientists have not been
able to figure out how the system starts, or what makes the rhythm know when to begin.