Table 1. Association of miR-223-3p levels with neutrophil infiltrate and CD31 expression.

	Neutrophil		P-value	MiR-223-3p staining			P-value	CD31 expression			P-value
	Low	Medium + High		Low	Medium + High	% high exp		Negative	Positive	% high exp
Control	6	2	0.042*	6	2		0.05*	8	0		0.03*
Early-stage T	2	20	0.001#	2	20	90	0.001#	17	5	21	0.2#
Advanced-stage T	9	4	0.999 ±	10	3	23	0.99 ±	3	10	77	0.001 ±

Statistical analysis: Fisher's exact test. *Control vs. Tumors. ^#Control vs. Early-stage Tumors. ± Control vs. Advanced-stage Tumors.

Quantification of neutrophil infiltrate, miR-223-3p staining and CD31 expression from a control group made of 8 healthy people, a group made of 22 HNSCC patients with early-stage (T1 or T2) tumors and a group made of 13 patients with advanced-stage (T3 and T4) tumors was performed by a trained pathologist as following. A sample was considered to display low expression if the percentage of positive cells was from 0 to 10%, median expression (med) if the percentage is between 10 to 50% and high expression if more than 50% of the cells were positive. Negative scoring for CD31 staining corresponds to less than 30% positive cells. Three random fields per tumor were analyzed. This contingency table highlights a correlation between the presence of neutrophils and the expression of miR-223-3p and an inverse correlation between the presence of miR-223-3p and the expression of CD31.