Many verses, some are just more known than the others
And Hanahaki:
https://fanlore.org/wiki/Hanahaki_Disease
Hanahaki disease is where a person develops flowers in their lungs due to unrequited love. As the disease progresses, the flowers grow and cause severe coughing and difficulty breathing. The condition can only be cured by either confessing love or having the feelings reciprocated. (Or as I read in almost all fanfictions, they can do surgery to remove the flowers, but it also removes their feelings for the person they long for) if your an ALNST fan(ivantill) I could give u a fanfic lol
today i discovered cakeverse