Figure 4. Linear regression curve showing no obvious correlation correlation between the percentage of patients treated with both PBC and EGFR-TKIs during the course of treatment and the OS in non-Asian (predominantly Caucasian) trials (r = 0.116, R² = 0.013, P = 0.588).

Mathematic equation of regression (based on a weighted model): OS (months) = 8.83 + 10.52 × (percentage of patients treated with both PBC and EGFR-TKIs).