2D	Two-dimensional
3D	Three-dimensional
ECM	Extracellular matrix
ER	Estrogen receptor
HER2	Human epidermal growth factor receptor
µg	Microgravity (r-µg, real microgravity; s-µg, simulated microgravity)
MCS	Multicellular spheroids
RCCS	Rotary Cell Culture System
RPM	Random Positioning Machine
RWV	Rotating Wall Vessel
PR	Progesterone receptor