This is the 4976th most frequent German word.
alzheimer
Alzheimer: A progressive neurodegenerative disease causing memory loss and cognitive decline.
Here, 'Alzheimer' is used as a noun to denote the disease itself.
Mein Großvater leidet an Alzheimer.
My grandfather suffers from Alzheimer's.
In this sentence, 'Alzheimer' acts as an attributive noun, describing the type of research (related to Alzheimer's disease).
Die Alzheimer-Forschung hat in den letzten Jahren Fortschritte gemacht.
Alzheimer's research has made progress in recent years.
Here, 'Alzheimer' functions as a noun used in possessive form to attribute the symptoms to the disease.