| Clue | Source | Date |
|---|---|---|
| Blood component that binds oxygen | ||
| Iron-rich blood pigment | LA Times Daily | 25 Dec 2020 |
| Iron-rich blood pigment | The Washington Post | 25 Dec 2020 |
| Blood pigment | New York Times | 19 Sep 2020 |
| Poet's in, losing time on recurrent idea | ||
| Iron-rich blood pigment | ||
| Deep red pigment | New York Times | 27 Jan 2018 |
| Deep red pigment | ||
| Pigment in red blood cells | New York Times | 17 Sep 2017 |
| Pigment in red blood cells | ||
| Deep red blood pigment | Universal | 02 Mar 2016 |
| Blood pigment | Universal | 30 Jul 2015 |
| Blood pigment | ||
| Complex red organic pigment | ||
| Blood pigment | ||
| Red blood cell component | ||
| Myoglobin component | ||
| Blood component | ||
| Deep red blood pigment | ||
| Blood component | ||
| Complex, red organic pigment | ||
| Deep-red blood pigment | ||
| Iron carrier in blood | ||
| Blood pigment | ||
| Red blood cell component | ||
| Deep-red blood pigment | ||
| Iron-containing pigment | ||
| Red pigment | ||
| Deep red | ||
| Hemoglobin pigment. |