Hopefully, after the considerable amount of these types of puzzles on this website, you would know the drill :0
Still, if you want you can review the rules:
- Find out what characteristic a Building Block Word™ has.
- In addition, don't forget to justify why I call it a "Building Block Word™".
The CSV version:
Building Block Words™,Not Building Block Words™ PROTEST, RALLY ILEUM, JEJUNUM PHENOMENON, CIRCUMSTANCE LEUKEMIA, MELANOMA ALARMED, TERRIFIED METRONOME, POLYRHYTHM THRESHOLD, ACTIVATION ASPIRATE, LABIALIZE HISTORY, PREHISTORY ARGUMENT, REBUTTAL GLUE, TAPE VALOR, BRAVERY SERVICE, MEMBERSHIP
Glycogen and cyst are Building Block Words™.