The rule goes:
If there is a positively charged amino acid at position 11 or 25 (according to public consensus - 12 and 29 in our alignment), then predict cxcr4, otherwise predict ccr5. The positively charged amino acids are R Arginine, K Lysine, and H Histidine.
The charge rule classifies our datset with 87.45% accuracy. It correctly classifies 237 out of our 271 test cases. Here is a breakdown of the the charge rule's class specific performance.
| TP Rate | FP Rate | Precision | Recall | Class |
| 0.757 | 0.054 | 0.897 | 0.757 | cxcr4 |
| 0.946 | 0.243 | 0.864 | 0.946 | ccr5 |