The median rate constant of AFP production by cancer cells (ω1) was numerically lower in PD than in PR-SD and CR (0.0002 vs. 0.0008 vs. 0.0016 C × day−1), whereas the median decay constant of AFP (0.10–0.12 day−1) was not different among the three groups and similar in all patients but one (Case-7, who showed the lowest AFP production rate and low AFP serum levels). This evidence concerns the gene AFP and cancer.