Simplify the following text for a Grade 10 native English-speaking person.
Original: Sensing of both the external and internal environments at the cellular level relies on signal transduction . Many disease processes , such as diabetes , heart disease , autoimmunity , and cancer arise from defects in signal transduction pathways , further highlighting the critical importance of signal transduction to biology , as well as medicine .
Simplified: A signal transduction in biology , is a cellular mechanism .