. 2020 Sep 8;15(9):e0238862. doi: 10.1371/journal.pone.0238862

Table 2. Effects of short-term spheroid culture as assessed by image analyses.

Tumor	Doses of Erlotinib (μM)	Number of Replicate Wells	Significance of Effects Observed in Image J Particle Analysis Data^†
1	0, 0.001, 0.01, 1 & 10	1	Spheroid Area: TIC^*
			Spheroid Number: None
			Average Spheroid Size: TIC^***
2	0, 0.001, 0.01, 1 & 10	1	Spheroid Area: None
			Spheroid Number: TIC^**
			Average Spheroid Size: TIC^*
3	0, 0.001, 0.01, 1 & 10	2	Spheroid Area: Well^*
			Spheroid Number: Well^*
			Average Spheroid Size: TIC^, Well^
4	0, 0.001, 0.01, 1 & 10	2	Spheroid Area: TIC^**
			Spheroid Number: TIC^, Well^
			Average Spheroid Size: TIC^***
5	0, 0.001, 0.01, 1 & 10	2	Spheroid Area: TIC^**
			Spheroid Number: TIC^***
			Average Spheroid Size: None
6	0, 0.001, 0.01, 1 & 10	2	Spheroid Area: TIC^****
			Spheroid Number: TIC^****
			Average Spheroid Size: TIC^****
7	0, 0.001, 0.01, 1 & 10	2	Spheroid Area: TIC^****
			Spheroid Number: TIC^****
			Average Spheroid Size: TIC^***
8	0, 0.001, 0.01, 1 & 10	1	Spheroid Area: TIC^*
			Spheroid Number: TIC^**
			Average Spheroid Size: TIC^****
9	0, 0.001, 0.01, 1 & 10	2	Spheroid Area: TIC^****
			Spheroid Number: TIC^****
			Average Spheroid Size: TIC^**
10	0, 0.001, 0.01, 1 & 10	2	Spheroid Area: TIC^****
			Spheroid Number: TIC^***
			Average Spheroid Size: TIC^, Well^

^† Time in culture, TIC; significance levels are indicated by:

*, P = <0.05;

**, P = <0.01;

***, P <0.001;

****, P <0.0001