Why do you think the presence of a specific type of keratin, an intermediate filament protein, in the bloodstream or lymph node is an indicator of metastasis of tumor cells?
A)Intermediate filaments are only found in tumor cells.
B)Keratin is only present if its specific cell type is also present.
C)Intermediate filament proteins cause cells to clump together.
D)None of the other answer options is correct.

Question

Quizplus · Accepted Answer

Keratin is a specific type of intermediate filament protein that is expressed in different cell types, such as epithelial cells. The presence of keratin in the bloodstream or lymph nodes indicates that cells from epithelial tissues, where keratin is produced, have entered the circulation due to the detachment from the primary tumor and invasion into the blood or lymphatic vessels, indicating metastasis.

Why Do You Think the Presence of a Specific Type