A positive pregnancy test can strike fear in the hearts of many men—but maybe more so if they're the ones taking it.

As one Internet poster discovered, home pregnancy tests can be a diagnostic tool for men, too. The tests, designed to detect the pregnancy hormone beta human chorionic gonadotropin, can also predict some types of testicular cancer.

Although not quite an Internet secret, the discovery made headlines when a poster on the social media site Reddit thought he was engaging in good ol' fashioned ribbing when he posted a comic about a buddy who took an ex-girlfriend's pregnancy test and found out he was expecting.

But, alas, the friend was not the next Thomas Beatie, the transgender man who became the world's first pregnant man in 2007.

After thousands of readers urged the poster's friend to get himself to a doctor, the poster returned with a follow-up comic noting that his friend was indeed diagnosed with a testicular tumor.

“Good Morning America” and other media outlets caught wind of the story, and physicians confirmed that the test could pick up troubling levels of HCG in men.

Just another example of how the scientific process—amplified by the digital age—can find new purposes for old discoveries.