During the synthesis stage of the cell cycle, a cell makes (replicates its own) DNA.
Economic profits equals total revenues minus the sum of explicit costs and implicit costs. Since explicit costs are already subtracted when arriving at the accounting profit, we can find economic profit by subtracting the implicit costs from the accounting profit.
The difference between the two can be attributed this way, implicit cost is an anticipated loss of revenue even before the whole transaction pushed through. These are not in reflected in cash but rather this is based on benefits that a certain investment seems very promising.