Antibody:	anti-p63
Detection system:	Secondary antibody coupled to horseradish peroxidase

Structure	Level	Pattern	Image	Note
TS21: ultimobranchial body	Present	Single cells	2A	Most cells lacked expression, and only expressed in a few cells.

Structure	Level	Pattern	Image	Note
TS21: ultimobranchial body	Present	Single cells	2B	Most cells lacked expression, and only expressed in a few cells.

Structure	Level	Pattern	Image	Note
TS21: ultimobranchial body	Present	Single cells	2C	Most cells lacked expression, and only expressed in a few cells (6.4 +/- 1.1).

Structure	Level	Pattern	Image	Note
TS20: ultimobranchial body	Present	Single cells	3A	Expressed in a few cells (6.2 +/- 1.3).

Structure	Level	Pattern	Image	Note
TS22: thyroid gland	Present	Regionally restricted	3B	Expressed in most of the cells (63.6 +/- 3.7) forming an oval cellular structure in the ultimobranchial body.

Structure	Level	Pattern	Image	Note
TS25: thyroid gland	Present	Regionally restricted	3C	Expressed in most of the cells (81.2 +/- 2.9), forming an abnormal vesicular structure within a cluster of Trp63-positive cells that were lined by monolayers of Trp63-negative cells in the ultimobranchial body.

Structure	Level	Pattern	Image	Note
TS25: thyroid gland	Present	Regionally restricted	3D	Expressed in an abnormal vesicular structure within a cluster of Trp63-positive cells that were lined by monolayers of Trp63-negative cells in the ultimobranchial body.

Structure	Level	Pattern	Image	Note
TS26: thyroid gland	Present	Regionally restricted	3E	Expressed in an abnormal bilayer vesicular structure consisting of an inner lining of Trp63-negative cells surrounded by an outer layer of Trp63-positive cells within a cluster of Trp63-positive cells in the ultimobranchial body.

Structure	Level	Pattern	Image	Note
TS26: thyroid gland	Present	Regionally restricted	3F	Expressed in an abnormal bilayer vesicular structure consisting of an inner lining of Trp63-negative cells surrounded by an outer layer of Trp63-positive cells.

Structure	Level	Pattern	Image	Note
TS21: ultimobranchial body	Present	Single cells	4A	Expressed in a few cells.
TS21: thyroid gland	Present		4A

Structure	Level	Pattern	Image	Note
TS22: thyroid gland	Weak	Scattered	4C	Sparsely expressed in both ultimobranchial body and primitive thyroid follicles as very weak signals.

Structure	Level	Pattern	Image	Note
TS22: thyroid gland	Weak	Scattered	5A	Sparsely expressed in both ultimobranchial body and primitive thyroid follicles as very weak signals.

Structure	Level	Pattern	Image	Note
TS22: thyroid gland	Strong	Regionally restricted	5B	Expressed in several cells at the periphery of the primitive thyroid follicles.

Structure	Level	Pattern	Image	Note
TS26: thyroid gland	Weak	Regionally restricted	5C	Expressed in some cells in the primitive follicles.

Structure	Level	Pattern	Image	Note
TS26: thyroid gland	Strong	Regionally restricted	5D	Expressed in follicular cells of primitive follicles but also cells surrounding the primitive follicle.

Structure	Level	Pattern	Image	Note
TS26: thyroid gland	Strong	Regionally restricted	7A	Expressed in an abnormal bilayer vesicular structure consisting of an inner lining of Trp63-negative cells surrounded by an outer layer of Trp63-positive cells.

Structure	Level	Pattern	Image	Note
TS21: ultimobranchial body	Present	Single cells		Expressed in a few cells.

Structure	Level	Pattern	Image	Note
TS27: thyroid gland	Present	Scattered		Expressed in thyrocytes and is scattered throughout the thyroid lobes.

Structure	Level	Pattern	Image	Note
TS27: thyroid gland	Present	Scattered		Expressed in thyrocytes and is scattered throughout the thyroid lobes.